Guide – GPR

Archaeology Techniques

Ground Penetrating Radar (GPR)

GPR for Archaeology

Introduction

Ground Penetrating Radar (GPR) is a variation on conventional radar, rather than into the air, a radio signal is directed into the soil and this is reflected by underground structural variations. It can be very good at detecting the structures of buried masonry structures as well as pits and in some cases artefacts.

Radar was famously developed for military purposes during world war two, and has been adapted for a variety of other purposes, including location of defects in concrete structures. GPR has proven very useful to archaeology where there are voids and substantial deeply-stratified masonry remains. It is particularly valuable on urban sites, ditches, cave structures, ancient mines or large landscape features such as dry river channels, but it is generally of less use in the softer and more finely-differentiated types of deposit encountered on many rural archaeological sites.

Description

High frequency pulsed electromagnetic waves (generally 10 MHz to 2,000 MHz) are used to provide information on buried features and remains. The wave energy is directed into the ground is reflected back to the surface from the edges of the features being scanned. The echoed signals are collected by the GPR equipment and the resulting data can be interpreted to show a map of the buried features and artefacts. The resolution of the scan and the depth of penetration vary depending on the wavelength used.

Integration of the GPR data with other surface geophysical methods, such as seismic, resistivity, or electromagnetic methods can provide a detailed map of the buried features, and a skilled interpreter can often conclude the exact size, nature and composition of the archaeological feature prior to excavation.

Increasingly, archaeological investigations use a combination of geophysical methods to improve the overall accuracy of the survey. Ground penetrating radar is a widely accepted technology for characterizing and imaging subsurface conditions.

Operation

A GPR survey is carried out by pulling a radar scanner across the ground, typically on a wheeled trolley. Readings are taken across a survey grid and then downloaded and plotted.

GPR uses high frequency pulsed electromagnetic waves typically from 10 MHz to 2,000 MHz. The electromagnetic wave is radiated from a transmitting antenna which is generally placed in direct contact with the ground and is designed to focus all the waves into the ground. The waves travel through earth at a rate which is determined by its electrical properties. The wave spreads out and travels downward, if it hits a buried object or change in soil composition, then part of the wave is reflected back to the surface, the extent of the reflection is proportional to the change in electrical characteristics of the buried materials. The rest and the wave energy continues to travel downward, further reflections may be generated as other objects or boundaries are passed through.

The wave reflection is captured by the GPS antenna, and can be recorded on a storage device for later interpretation. Often, the GPR data is one shown as signal versus amplitude, and is referred to as a trace. A single GPR trace consists of the transmitted energy pulse followed by pulses that are received from reflected waves, these are known as layers. A scan is a trace where a colour or grey scale has been applied to the amplitude. As the antenna(s) are moved along the survey line, a series of traces or scans are collected at discrete points along the line. These scans are positioned side by side to form an underground display profile.

GPR Components

GPR equipment consists of a radar control unit, transmit and receive antennas, and a suitable data storage device. The radar control unit generates trigger pulses to the transmitter and receiver electronics in the antennas. These pulses allow the antenna electronics to generate a sampled waveform of the reflected radar pulses.

The transmit antenna generates the pulsed wave and directs it into the ground, the receive antenna picks up the reflected pulses and passes these back to the control unit, which converts this information into signals suitable for logging.

Use of a specific antenna is determined by the required results. A GPR will normally come with a range of antenna, which allow for a range of frequencies to be used, typically these will range from 10 to 2000 MHz. Higher frequency means better resolution, but with more significant electromagnetic wave attenuation in the environment, resulting in lower sounding depth; and vice versa – lower frequency may lead to a larger penetration depth at the sacrifice of poorer resolution. Lower frequency operation produces larger initial insensitivity area (“blind” zone) of a GPS.

Comparison of frequencies used and typical responses

Frequency range
2 GHz
900 MHz
500 MHz
300 MHz
150 MHz
75 MHz
38 MHz
Resolution, m
0.06-0.1
0.2
0.5
1.0
1.0
2.0
4.0
“Blind” zone, m
0.08
0.1-0.2
0.25-0.5
0.5-1.0
1.0
2.0
4.0
Depth, m
1.5-2
3-5
7-10
10-15
7-10
10-15
15-30

GPR systems are digital devices and logging is done with digital devices for post survey analysis. Many data loggers also come with display electronics and allow in the field data manipulation. Often this is done with a laptop computer. In order to display the data for interpretation, it must first be filtered to remove noise, it is normal to store the raw data so that a variety of filter options can be tried later.

Operating Modes

The most common way of using a GPR as the reflection profiling method. Here, a radar wave is transmitted, received and recorded each time the antenna has been moved a fixed distance across the ground. It should be noted that GPR can also be used on other surfaces such as water.

Another way of using GPR is in three-dimensional operation, which collects data samples at closer intervals of less than 1 meter. This result in very large amounts of data which can be manipulated to three dimensional model of the survey area.

Transillumination is a rare but sometimes effective way of using GPR, it involves placing the transmitter and receiver on opposite sides of the material to be surveyed and can provide very accurate measurements of mines and other shafts.

Data Display and Interpretation

Three buried objects in a two dimensional display

In order for the correct interpretation of underground features it is essential that the data is displayed in a way that easily facilitates this. There are three of displaying the results of a GPR survey – 1) a one-dimensional trace, 2) a two dimensional cross-section, and 3) a three-dimensional display.

One-dimensional traces

The wiggle trace (or scan) is the building block of all GPR survey data. A single trace can be used to detect objects (and determine their depth) underground. By moving the GPR antenna over the ground and recording traces at a fixed spacing, a recording of several sections is obtained.

Two-dimensional cross sections

Wiggle trace displays are often impractical to display due to the number of traces required to make up meaningful data and scan displays have become the standard form of two dimensional display of GPR data. A scan display is created by assigning a colour to amplitudes displayed on the trace.

Three-dimensional displays

Three dimensional displays are created when the GPR traces are recorded at different positions ground surface. Data can be recorded along profile lines, in the case of continuous recording, or at discrete points along the surface in fixed-mode recording. Once 3D block views have been produced, they can be observed from a variety of viewpoints and ways, including solid block or block slices.

Creating a good three dimensional view is a very useful way of analysing the results of a GPR survey, but takes the most processing power and time. Careful choice of colour coding scheme and noise filtering is an important part of the image generation process.

Costs

The cost of GPR systems vary widely depending on their complexity. Most systems fall in the £10,000 to £35,000 range.

Guide – Resistivity

Archaeology Techniques

Resistivity

The electrical resistance of the Ground is almost entirely dependant upon the amount and distribution of moisture within it. Buried remains affect this distribution and can be detected with instruments. Stone, for example, is more moisture resistant than a clay subsoil or the filling of a ditch. These resistivity differences can be detected and when overlaid on a map will often give a plan of buried remains.

Resistivity survey methods have been used to detect both natural and archaeological features since the techniques discovery in 1946.

When one encounters a soil resistivity survey in progress, several thoughts spring to mind. How can objects deep under the ground be detected by electrodes inserted only a few centimetres? And why are four (sometimes five) electrode probes needed? Do differing types of soil affect the precision of the readings?

This guide aims to provide sufficient background information to allow the lay person to understand the basic principles of resistivity survey for archaeology.

First Principles

Those who remember physics lessons in school may remember that when an electrical voltage is applied between the ends of an electrical conductor such as wire, a current flows through it; the size of the current depending on the resistance of the conductor. The symbol for resistance is R, measured in ohms (often represented by the Greek letter omega).

Water, in its natural state, is an insulator. However, with a little salt added, it soon allows current to flow. Chemicals which have this effect on water are known as electrolytes. The resistance of soil is almost entirely dependant on its water content and the electrolyte “mix” it contains. Most of its other components, such as stone, are largely insulators. Buried wood generally tends to attract water and so reduces the resistance in that area.

Resistivity is a uniform measure which allows the resistance of different substances to be compared. It is defined as the resistance of a cubic meter of material when a 1 volt charge is applied between the two opposite faces of the cube. The unit of resistivity is the ohm metre, its symbol is the Greek letter rho.

The resistivity of soil can vary from 1-10 ohm-metres; porous rocks 100-1,000 ohm-metres and non porous rocks anything from 10k to 10m ohm-metres.

Contrary to how it may first appear, current does not flow through soil as a direct path. Current flowing between two electrodes in soil will spread out into a myriad of paths rather like the force bands surrounding a magnet. The total resistance is a sum of the resistance offered down each path. It can be seen therefore that a ditch cut through a rock base will show lower resistance in surface measurements than the natural soil and rock layer around it. In fact, the lower the resistance the deeper the current will travel – due to the like charged particles repelling each other, thus causing a wider spread of current.

Technically, resistivity measurements could be made using a household resistance meter. A calculation would be required to work out the resistivity and indeed some of the first resistivity devices used by archaeologists were based on an electrician’s “Megger” – a device normally used to certify domestic electricity circuits. However, due to design limitations these devices are generally unsuitable for soil resistivity measurement.

Measuring Soil Resistance

Measuring the resistance of soil presents us with problems. The electrodes applying the current have a small contact area compared to the volume of ground to be measured. At its surface soil tends to be dry, thus providing a poor contact medium. These effects create a much higher resistance in the immediate area of the electrodes, which would tend to cancel out any reading from the ground in between.

The solution to this problem was found by creating a probe with four electrodes. Known as the Wenner system, these are placed at equal distance in a line – the outer two apply the current, the inner two measure the voltage of the ground. These two measurements – voltage and current – are used to calculate the ground resistance (R=V/I).

In addition to this a high impedance measuring circuit helps take into account variations in surface contact conditions. An AC circuit is used as DC current would effectively turn the soil into a battery and mess up the readings. A further refinement uses a phase-sensitive rectifier to cancel out other interference.

Types of instruments

Manual Balance Instruments

These early instruments used an on-board dial to allow the resistance to be matched and noted; often the probes were pushed in individually. In some cases a rotary switch and a five probe design allowed a measurement to be taken each time a single probe was moved. Often two skilled operators were required.

Automatic Instruments

In general, manual balance systems have been consigned to the past, thanks to electronic devices such as data loggers which automatically sample and store the measurements, and the creation of a probe ‘cradle’ which allows an individual to survey a field at near walking speed.

Data Loggers

With a data logger, every time the probe cradle is inserted into the soil, a button is pressed to take a sample. The data logger – an electronic device attached to the cradle – takes the resistance readings and stores them in sequence.

Later, either on site or in the office, these samples can be plotted against a map to provide a clear picture of the resistivity changes of the subsoil, often giving feature markings so clear that little confirmation excavation is needed.

Laptop Computers and Beyond

The advent of the laptop and sub-laptop computer, together with the ability to provide data logging and sampling onboard, will ultimately create a cradle capable of giving a “live” display of the underground resistance topology. The technology for this advance exists currently, but will need a little development before it can be realised.

Resistivity for Archaeology

A feature of high resistance buried in the ground will cause the resistance of the overall local area to increase, this is known as a “positive anomaly”. Conversely, a feature such as a rock cut ditch will lower the overall resistance and is known as a “negative anomaly”.

In the early days it was assumed that based on the above, features such as stone foundations and walls would always give high resistivity readings and therefore be positive anomalies. However experience has shown that whilst this can be the case, often other factors such as the features geometry, associated deposits, soil moisture content and electrode configuration can cause complications to this rule.

However, a significant amount of research effort has created a range of designs which offer a robust and reliable surveying tool.

Electrode Configurations

The first experiments with soil resistance were carried out by Frank Wenner in 1916. His original four electrodes in a line configuration with two current electrodes to apply power (C1,C2) and two potential electrodes to measure resistance (P1,P2) has been adopted and modified by archaeologists based on the results of extensive testing.

During testing, it became clear that for some features the Wenner and related probe configurations were not effective at detecting some types of underground features. Narrow features were found to show double or even treble readings.

As a result of this a wide range of electrode configurations have been evaluated giving archaeologists the option of a range of electrode configurations to suit the ground and type of feature.

The Wenner configuration is still a commonly used configuration, as it offers good all round functionality for most types of submerged features. The wenner configuration can sometimes exaggerate the width of the anomaly and is susceptible to misinterpret some high resistance features.

C1 P1 P2 C2

Wenner electrode configuration

For very shallow features, the Double Dipole configuration has been shown to give particularly good results, this configuration, also known as the Wenner beta configuration is created by taking the Wenner configuration and swapping on current electrode for a potential electrode.

C1 C2 P2 P1

Double dipole electrode configuration

A more recent development, the Twin Electrode configuration sees the Wenner design cut in half and provides for a half size cradle as well as almost eliminating some of its inaccuracies. With the twin electrode configuration, two probes are fixed at a static point to one side of the test area. The other two probes are attached via a long lead and are moved around the survey site. This design helps to eliminate the exaggeration of high resistance features.

C1 C1 – – – – – – – – – – – – – – – – – – – -C2 P2

Fixed Mobile probe

Twin electrode configuration

One other electrode configuration worthy of mention is the Square Array, this was developed as a solution to the poor response given by the Wenner configuration to small buried objects. With this configuration the probe looks like a small table and tends to be used in more specialist circumstances.

C1 C2

P1 P2

Square Array configuration

The Impact of Soil

Now that we have a better understanding of the relationship between the buried feature and the types of probes used for resistivity, it is important to understand the effect different soils and moisture levels with readings.

The structure of soil

Generally, when we are talking about soil, we are considering several different factors, each of which are inter-related. Firstly, the top layer of soil is usually a loam type material with varying amounts of other materials either due to natural deposition or related to the natural bedrock. The actual resistivity of this soil is a combination of this soil composition and the retained moinsture at the time of the survey. The level of moisture retained by soil is a result of that particular soils natural drainage, and the drainage provided by the underlying bedrock.

In some times of the year, the soil effectively becomes waterlogged and this will result in many features being hidden by the overall low resistance of the soil

The following section illustrates the impact of bedrock on a features resistivity and discusses the impact of rainfall in order to identify the likely results for a particular feature as well as proposing the best time of year to survey for each bedrock type.

Bedrock type
Feature
Dimensions
Anomaly type
“Season”
Best
Sandstone
Ditches
W1-4m D3m
Low
Jun-Sept
July
Clay
Rubble Wall
W10m D1m
High
Jun-Nov
Sept
Limestone
Stn Coffin
W.5m D1.5m
High
Jul-Oct
Oct
Chalk
Ditch
W18m D6m
Low
Dec-Jun
Mar-Apr
Chalk
Ditch
W2.5m D1m
High
Jul-Nov
Sept
Chalk
Ditch
W6m D2m
Low/High
Dec-June
Mar-Apr

The Best “Season”

The above table gives example responses for types of anomaly and time of year. The first point to note is that features provide differing levels of response throughout the year. The main reason for this is the amount of rain held in the soil. As soil becomes soaked its resistance lowers until the readings from many features become “swamped” or hidden by this low resistance (low resistance features will disappear once the surrounding soil reaches the same resistance. Also hi resistance features may go by unnoticed when surrounded by very low resistance soil).

The amount of moisture retained by the soil is largely dependent on two things – amount of rainfall and drainage. Rainfall is typically seasonal, thus over the winter months many sites became waterlogged and unreadable.

The drainage for a particular site is dependent on many localised factors such as slope of the land. The underlying bedrock however commonly plays a significant role in determining the soils water content. An impervious rock such as sandstone will typically retain moisture for longer and therefore the resistivity “season” is shorter. By the same reasoning each local area will have a best time to survey depending on the local drainage and recent rainfall.

The size and nature of the buried feature also has an impact on the definition shown by a resistivity survey. Stone tends to have a higher resistance than the low resistance soil and even with relatively high resistance bedrock such as clay. Ditches generally always show a low resistance, the deeper the ditch the lower the resistance since deep ditches cut through the bedrock, lowering the depth of the low resistance fill.

Chalk can give conflicting results due to its structure. When it is dry, small ditches will tend to show a low resistance reading. However, chalk can act like a sponge when waterlogged, changing its resistance “form” from damp chalk to that of chalky water. In these conditions the bedrock becomes very low resistance and the ditch reads as a high resistance anomaly. Furthermore it has been found that in some cases due to the local water table the anomaly can fluctuate between high – neutral – low readings throughout the year and it is with this in mind that in chalk areas two resistivity surveys approximately. six months apart are recommended (spring and autumn).

Guide – Hidden Remains

Hidden Remains

Identification of features is simplified when the full extent of remains such as earthworks, can be easily seen. However, once the roof has gone, the walls perished or robbed, the interior burnt and the wreck left to perish for hundreds of years, the remainder flattened and used as a field for crops, the job of recognition is made all the more difficult. Fortunately, even without specialist equipment, there are a number of techniques that can be used to shed further light on features under investigation.

Field Markings

Ray Selkirk

Old foundations of walls are often found buried, gods creatures as well as the elements can accumulate a lot of soil, given the right ground conditions. The rate of burial will differ in open country to that in towns, where each generation flattens buildings and starts again on top of the rubble, the ancient habitation-layers can be twenty or thirty feet below the modem surface.

It is well known that under certain conditions, tell-tale marks manifest themselves in open country and if viewed from above, the shapes of these marks often reveal the location and identity of buried features. These give-away marks can be seen as differential colouring of vegetation above buried features (crop marks); white-outlined shapes produced by a thin dusting of snow collecting in slight hollows, or drifting along ridges (Snow marks); shapes visible in bare ground where the farmer has filled in an old ditch with a different coloured soil (soil marks); and shadowy shapes produced by low angle suimght outlining undulations almost imperceptible at ground level (shadow marks).

These manifestations were observed long before the development of aeroplanes: about 1740, the antiquarian, William Stukeley was ridiculed when he said that from a hilltop, he could see the distinctive shape of a Roman temple in a field of corn. Pioneer balloonists also reported similar sightings but it was not until the tremendous expansion of aviation in the 1914-18 World War that serious notice was taken of the phenomena. The various types of marks are explained as follows:

Crop marks

For crop marks to show, two conditions must be met. Firstly, the right type of crop must be planted in the field which contains the hidden archaeological site (cereal crops give the best results by far), and secondly, a drought or period of dry weather be experienced. The ancient peoples were enthusiastic ditch-diggers and even though infilled, these deep cuttings in the subsoil retain water, and during dry weather, the roots of a cereal easily penetrate the loose infill with the result that the crop over the ditch grows taller, thicker and of a deeper shade of green. This is known as a “positive crop mark.” Where the hard subsoil has not been disturbed, the crop’s roots reach the level of the subsoil and stop, resulting in a uniform shade of medium green.

Over old foundations or road metalling, the crop grows stunted and of a yellow-
green colour. This is a “negative crop mark.” When a cereal crop is ripe, the positive crop mark is still visible as a deeper gold colour and the negative mark as a more watery yellow.

What Stukeley had seen from his hilltop was the crop mark of a Roman temple. About the same period, negative crop marks were reported in France over the ploughed-out remains of circular burial mounds. On these, plant growth was sparse and they were known locally in northern France as danses defees (fairy dances).

Even after the crop is harvested, the thick growth over the infilled ditch can be seen as a deeper colour in the remaining stubble and a suitable name for this would be a “stubble mark.” Crop marks can show up in plants other than cereals, such as peas and beans or sugar beet, but the contrasting marks in these, and other crops are much inferior to those produced by wheat, oats and barley.

Soil marks

These marks are useful in winter and do not rely on a combination of cereal crops and a drought. Quite often, when a farmer has infilled an old ditch, the soil he has used is of a different colour and is easily visible from an elevated position. Sites which show-up as soil marks in bare fields in winter invariably produce crop marks in the other seasons if the right conditions are met.

Shadow marks

Many fields are in permanent pasture and have not been cultivated for hundreds of years or even longer. If the surface of such a field contains very slight undulations such as the last remnants of ancient earthworks and ditches, these may be invisible to the observer at ground level, but when viewed from an aircraft in low-angle sunlight in early morning or late evening and especially in winter and spring when the grass is short and the Sun’s altitude small, the shape of the whole habitation appears as if by magic. One side of the almost flattened earthwork is highlighted and the other is in shadow. The almost invisible ditch likewise has one side highlighted with the other in shadow. Thus the whole shape of the site is revealed.

The marks show best when viewed from above, down-sun of the site, so surrounding hills would be an advantage, more determined searches for shadow marks done by air should be conducted with the aircraft being flown in a series of advancing circles.

The British archaeologist Sir Leonard Woolley (1880-1960), who excavated Ur in 1922-9 had been attempting earlier to locate an ancient Egyptian cemetery below the Second Cataract of the Nile near Wadi Haifa. This site had eluded Sir Leonard and the expedition leader, D R Maclver. but one evening, after a hard day’s search, the two men climbed a hill to view the sunset. In the low-angled sunlight, strange circles, invisible at ground level, appeared at the base of the hill. As Sir Leonard descended, the circles disappeared, but Maclver, who had remained behind was able to direct him to the positions with hand signals. Sir Leonard marked them with small cairns. Next day, workers excavated the marked positions and found a tomb at every one.

When crop mark conditions are present, the corn or barley grows higher over the infilled ditch and in low-angle sunlight, this casts a shadow, and an excellent combination of crop marks and shadow marks is obtained.

During the nineteenth century, soldiers who had served at Gibraltar said that when they looked from the top of the rock, towards the Spanish border to the north, they could see the remains of the old Spanish lines which were invisible at ground level.

Snow and frost marks

Snow marks are rather like shadow marks etched with a white paint brush. Faint traces of earthworks are necessary, and in a light dusting of snow, the ditch is painted with a bright white band. A bank, even a slight one, causes drifting, and a combination of snow marks and low-angle-sun shadow marks can produce a most striking result.

Heavy snow obliterates all signs of the site. During the thaw, the snow remains in the ditch long after the remainder of the field is clear. Possibly the latter would be better called “melt marks.” Closely related to melt marks are “frost marks”: when a field is covered with frost, ancient stonework below ground level retains heat better than the surrounding soil and the line of the foundation is revealed by the absence of frost, and shows as a dark line.

Parch marks

Crop marks do not normally show up in grassland, but during a period of hot dry weather, lawns and pastures which hide buried roads or stone foundations, reveal their secrets when the grass above the stonework or metalling becomes scorched and turns brown.

Plant marks

Some wild flowers and weeds like to grow over old stonework, and quite often, a field with a buried line of stone develops a prominent line of flowering weeds above invisible foundations. Poppies have an affinity for wetter infilled ditches outside the ramparts of Iron Age British hillforts.

Similarly, nettles like highly furtile, deep soil and have a tendancy to cluster in ditch fillings and locations rich in neutrients, such as waste sites and areas with large amounts of buried decaying wood. In moorland areas the difference in soil depth can be easily seen as heather gives way to ferns.

Trees can also be good indicators, many boundaries have been lined with thorn trees since Iron Age times, the presence of these can sometimes help confirm earlier boundaries, in some cases, the enclosure walls of hillforts may have been lined with thorn. One tree – the Yew can be particularly useful in dating a site, this is an extremely long lived tree, which also has highly poisonous leaves. It is reckoned that for every foot around it’s girth a Yew may have lived 30-40 years. Another adage is that it grows a bough for every thousand years.

Wind marks

When positive crop marks are present, the cereal growth above the ditch is higher than that over the rest of the field. Strong winds can strike the projecting tops, and the end result is that the corn is flattened along the lines of the ditches.

Spurious marks

Where horses or goats have been tethered, they may have grazed circles of grass which can look like the marks of Iron Age huts when viewed from an aircraft.

Circular bands of dark grass caused by fungi (fairy rings) can also look like the marks left by ancient rondavels.

A straight track of stunted grass across a field need not be evidence of an ancient road. It may be an animal path, the cattle having been kept in a straight line by a thin electrified wire, invisible to the airborne searcher.

Guide – Visible Remains

Visible Remains

“The identity of an earthwork can be determined to a certain extent by the shape of the field marking that is left. If it is square or rectangular with rounded comers, it is highly likely that the constructors were from the Roman army. If it is an irregular quadrilateral with a gateway on the eastern side, then the originators were Roman-period British (Celtic) farmers. Circular ditches usually surrounded the defended pre-Roman Iron Age Celtic settlements. Other archaeological sites such as prehistoric religious monuments (henges) and burial mounds (barrows) had their own distinctive shapes.” Ray Selkirk.

There are a large number of earthwork types which are related to the Iron Age, some include stonework or ditches but all can be included as earthworks. The major feature types are identified here, a full index of feature types is available in our  Glossary of prehistoric features.

Houses

Typically circular in plan, some square and rectangular buildings have also been found.

On upland soils where nothing has been built since the huts dissapeared, the ring grooves or stone foundations may still be seen on the ground, or by the outline of an earth bank or ditch.

Hut circles may contain a central hearth or hearths, and in others, examples have been found of drains, sumps and paved stone floors.

In lowland areas, sites of homesteads may be detected on grassland by circular or rectangular ground impressions, and by the sharper outline caused by rings of lusher (ditch) or less lush (stone) grass.

Houses can sometimes be identified by an area of leveling on a slope.

Enclosures

Some settlements were surrounded by a stone wall, some were enclosed by a palisade bank and ditch, others were undefended. Other enclosures, such as above, may have been animal enclosures.

Within the interior of the enclosure there may be visible signs of storage or refuse pits.

Linear depressions may indicate the position of a former protective ditch or ditches.

Old trackways and routes to the fields may be detected on the surface of the ground. The lines may show up more clearly in certain lighting conditions.

Some settlement areas seem to have been simply delineated on one or more side with a wall and ditch, in an alignment more likely to have been for boundary definition than defensive purposes.

Celtic fields and lynchets

The Celtic fields and settlements of Grassington.

These are squarish to rectangular plots ranging in size, usually, from .25 to 2 acres (0.1 – 0.8ha).

The field boundaries are usually marked by ditches, low banks or walls of stone.

The fields may have a few circular hut foundations scattered among them.

The strip lynchets of Reeth.

After constant ploughing, even on gentle slopes, the soil would creep down forming terraced banks or lynchets.

These are commonly confused with medieval fields which have ridge and furrow also.

Hillforts and Defended Enclosures

A hillfort is an enclosure, apparently fortified, sited in a position to achieve the ultimate defensive advantage, and usually not less than .5 acre (.2Ha) in enclosed area.

Mam Tor

Although the general perception is that all Iron Age fortifications are called hillforts, in actuality hillfort is a single category under the general term clssification of Defended Enclosures. Often a fort can fall into several categories.

Univallate hillforts are defended by a single rampart of earth and / or stone rubble, with or without a trench or ditch, and following the contours or the hill. These hillforts have one or two entrances.

Carl Wark

Promontory forts are dramatically situated on headlands or on hill spurs protected by ramparts as well as by the existing natural features, such as cliffs and steep slopes.

Almondbury

Multi vallate hillforts developed two or more ramparts with accompanying ditches, and with elaborately defended entrance points.

Multiple Enclosure forts were built on hill-slopes with widely spaced earthworks.

Some of the hillforts were established in the Bronze Age, and continued as a characteristic feature of the Iron Age.

Many of the earthworks and ditches are still massively impressive, despite the ravages of time, weather and farming operations. In other examples the earthworks have been levelled.

Wincobank

Where there where no hills, or for other tactical reasons, some forts were built on low ground with particularly strong ramparts.

Some hillforts show evidence that the defensive walls have been vitrified, the stone facing melted by incredibly high temperatures.

In areas where stone was available, the ramparts were constructed of stone or a core of rubble faced with stone blocks.

Although hill forts were a significant feature of the Iron Age, very few have been shown to have continued use, many were abandoned after a few generations of use, some after only a few years. The manner of construction of the hillfort is more indicative of the circumstances of it’s building, rather than an indicator of its date (i.e. univallate forts are not necessarily and early design).

Guide – Glossary

Glossary of prehistoric features

This section was compiled with the help of the English Heritage NMR record. It currently includes descriptions for those Military, Domestic and Agricultural features that would have been in existence up to the Roman Period in Britain.

Primary Name
Alternate Name(s)
Description
ALTAR
An elevated table or podium on which to place or sacrifice offerings to the deities.
AMPHITHEATRE
Arena
An oval or circular building with seats rising in tiers around a central open space. Used for religious ceremonies, entertainment, training and armed combat contests.
ARD MARKS
Ardmarks
The subsoil traces of prehistoric cultivation, presumed to have been caused by the use of an ard to till the soil.
AUXILIARY FORT
A permanent Roman fort enclosed by a number of ditches and ramparts, used to house a garrison of auxiliaries.
AVENUE
A monument consisting of parallel lines of banks, ditches, stones, timber posts or trees which appears to mark out an approach to another monument or monuments. Use specific type where known.
BANK BARROW
A poorly understood Neolithic monument comprising a very long, narrow earthen mound. They may be of single-phase construction, or represent the addition of a linear extension to the bank of an existing Long Barrow.
BARRACKS
Barrack Block
A building used to house members of the armed forces
BARROW
Burial Mound, Hlaew, Howe, Knowe, Tumulus
Artificial mound of earth, turf and/or stone, normally constructed to contain or conceal burials.
BATTLEFIELD
The field or area of ground on which a battle or skirmish was fought.
BIVALLATE HILLFORT
A hilltop enclosure bounded by a double line of ramparts.
BOUNDARY CROSS
A sculpted cross, or a cross incised into stone or trees, to mark a parish boundary.
BROAD RIDGE AND FURROW
Long parallel soil ridges in excess of 5 metres across separated by furrows, formed by using a heavy plough capable of turning the soil
BURNT MOUND
Boiling Mound
A mound of fire-cracked stones, normally accompanied by a trough or pit which may have been lined with wood, stone or clay. Assumed to be locations where heated stones were used to boil water primarily for cooking purposes.
CAIRN
A monument featuring a bank or mound constructed primarily of stone.
CAIRNFIELD
A group of cairns occurring within close proximity to each other. Use for instances where the majority are clearance cairns. Also index specific types where known.
CAUSEWAYED RING DITCH
A monument comprising an irregularly circular enclosing ditch, interrupted by several causeways, surrounding a central circular area used for funerary activities, often concealed originally beneath an earthen mound. Index with barrow type where known.
CELTIC FIELD SYSTEM
A fairly regular system of small rectangular fields. Examples may date from the middle Bronze Age to the Roman period. The word ‘Celtic’ carries no chronological or cultural connotations in this context.
CHAMBERED BARROWS
A Neolithic burial monument comprising a stone-built chamber within an earthen mound.
CHAMBERED LONG BARROW
Gallery Grave, Trascepted Gallery Grave
Neolithic burial monument comprising a stone-built chamber within a rectangular or trapezoidal earthen mound.
CHAMBERED ROUND BARROW
Gallery Grave, Trascepted Gallery Grave
A Neolithic burial monument comprising a stone-built chamber within a circular or sub-circular earthen mound.
CHEVAUX DE FRISE
A system of stones or wooden obstacles placed close together to impede the advance of enemy forces.
CIVITAS CAPITAL
A planned administrative capital for local government which provided amenities for the Roman and peregrine (non-Roman) inhabitants of the town.
CLEARANCE CAIRN
Field Clearance Cairn
An irregularly constructed, generally unstructured, mound of stones. Often, but not necessarily, circular. Normally a by product of field clearance for agricultural purposes.
CLIFF CASTLE
An enclosure created by constructing one or more lines of ramparts across a promontory which projects into the sea.
CLOTHES LINE ENCLOSURE
A small rectangular or sub circular area or areas bounded by an earthwork, ditch or similar boundary, where one side is formed by an existing linear boundary, forming a pattern reminiscent of clothes hanging from a washing line.
COLONIA
A town founded as an act of government by charter to house Roman or Latin citizens, usually retired legionaires who had been granted land within a territorium.
COOKING PIT
A pit which shows evidence for having been used for cooking. Often contains charcoal, burnt bone fragments etc.
CORD RIG
Narrow ridges representing the surviving surface traces of later prehistoric cultivation.
COURTYARD HOUSE
Yard House
A building or buildings ranged around a courtyard on at least three sides. They occur in the Iron Age, as well as being an influential plan type of house from the 15th century onwards. Index with appropriate period.
CRANNOG
Lake Dwelling
An island, partly or wholly artificial, built up by dumping timber, earth and stones onto a lake or river bed. Often revetted with timber piles or palisade.
CROSS
Churchyard Cross, Market Cross, Causeway Cross etc.
A free-standing structure, in the form of a cross (+), symbolizing the structure on which Jesus Christ was crucified and sacred to the Christian faith. Use specific type where known.
CULTIVATION MARKS
Manmade marks or earthworks which provide evidence for agricultural cultivation.
CURSUS
A long narrow rectangular earthwork enclosure of Neolithic date, usually defined by a bank and ditch and presumed to be of ceremonial function. Known examples range in length from less than 100m to c.10km.
D SHAPED BARROWS
Not a round barrow ploughed out at one end, but a specific type, the flat edge being additionally defined by stone slabs
DYKE (DEFENCE)
Dike
A defensive or boundary earthwork.
EMBANKED AVENUE
A monument consisting of parallel banks, normally accompanied by ditches, which appears to mark out an approach to another monument or monuments.
ENCLOSED OPPIDUM
A site with one or more defensive earthworks, often at a river crossing incorporating natural features which define parts of the curtilage.
ENCLOSED SETTLEMENT
Enclosed Platform Settlement, Gussage Style Enclosure, Itford Style Enclosure, Martin Down Style Enclosure, Springfield Style Enclosure, Wooton Hill Style Enclosure.
A site used primarily for domestic purposes on at least a semi-permanent or seasonal basis, and which has been surrounded by a bank and ditch, palisade, or some other form of enclosure. Use more specific type(s) where appropriate.
FIELDWORK
Military Earthwork
A usually temporary earthwork or fortification, the latter constructed by military forces operating in the field. Use more specific type where known.
FOGOU
Fougou
Underground chambers and stone passages of Iron Age date found in South West England.
FORT
Praetentura, Praetorium, Roman Fort
A permanently occupied position or building designed primarily for defence.
FORT ANNEXE
A small enclosure built onto the perimeter of a Roman fortress
FORTIFICATION
A usually permanent defensive work.
FORTLET
Fortilace, Roman Fortlet
A fortified Roman site, usually under 1 hectare in area, strategically situated, housing small military patrols, often defended by a rampart, one or two ditches and a gate.
FRONTIER DEFENCE
Curtain Frontier, Frontier Works
A system of fortifications constructed along a national frontier to contain the local population, as well as keep out undesirable raiders eg. Offa’s Dyke. Use with more specific monument type where known.
FUNERARY SITE
Site types normally or frequently associated with burials which in some instances may have had solely religious or ritual functions.
GRAIN STORAGE PIT
A pit where grain is stored.
GYRUS
A sunken arena used by the Romans for training cavalry horses and recruits.
HIGH CROSS

A churchyard or memorial cross set on a long shaft
HILLFORT
Contour Fort
A hilltop enclosure bounded by one or more substantial banks, ramparts and ditches. Use more specific type where known.
HILLTOP ENCLOSURE
A substantial area of ground surrounded by slight univallate earthwork often interpreted as stock enclosures or as sites where agricultural produce was stored.
HUT
Beehive Hut
A building of basic construction, usually smaller in size than a house and constructed from a variety of materials such as mud, turf, branches, wood, brick, concrete or metal. Use more specific type where known.
HUT CIRCLE
Hut Walls, Stone Hut Circle
A round house indicated by the presence of a low, roughly circular bank of turf, earth or stone, which formed the base of the walls. Characteristic of the later prehistoric period. Where several occur together the term HUT CIRCLE SETTLEMENT is used.
HUT CIRCLE SETTLEMENT
Hut Group
A settlement consisting of several hut circles, either grouped together or dispersed. Characteristic of the later prehistoric period. Use specific forms where supported by the available evidence.
HUT PLATFORM
Levelled or terraced area of ground presumed to have been the site of a house or hut.
HYPOCAUST
A Roman under-floor heating system in which hot air heated by a stoked furnace, flowed through channels, created by either raising the floor on pillars of brick and tile or cutting channels into the concrete floor and tiling over them.
LAKE VILLAGE
Lake Settlement
A settlement located on or near to the shores of a lake. Buildings associated with lake villages are usually raised on piles to prevent them from being flooded.
LEGIONARY FORTRESS
Praetentura, Praetorium, Roman Fort
A large, fortified permanent Roman military base, made of timber and stone, surrounded by a rampart and ditches.
LINEAR CLEARANCE CAIRN
A long, narrow, irregularly constructed and generally unstructured mound of stones. Normally a by-product of field clearance for agricultural purposes, though prehistoric examples may include burials and other deposits.
LONG BARROW
Earthen Long Barrow
A rectangular or trapezoidal earthen mound of Neolithic date, usually accompanied by flanking or encircling ditches, and normally associated with human remains. Mound construction and associated features vary considerably in type and complexity.
LONG HOUSE
Byre House, Domus Longa, Long House
A barn and dwelling under one roof, with a cross passage between them.
LYNCHET
Lynchet, Lunchet Field System, Negative Lynchet, Positive Lynchet
A bank formed at the end of a field by soil which, loosened by the plough, gradually moves down slope through a combination of gravity and erosion.
MARKET CROSS
Market Cross Shelter, Butter Cross
A cross found in a market place.
MIDDEN
A refuse heap.
MILECASTLE
A small, walled fortlet, situated every Roman mile along the length of Hadrian’s Wall to defend a gateway allowing the passage of people and as a garrison to accommodate patrol troops.
MILEFORTLET
A free standing small turf and timber fortlet, situated every Roman mile along Hadrian’s Wall.
MULTIPLE ENCLOSURE FORT
Hillslope forts with wide spaced ramparts
MULTIVALLATE HILLFORT
Large Multivallate Hillfort, Small Multivallate Hillfort
A hillfort enclosure with defences composed of more than one bank and ditch
MUNICIPIUM
A town for citizens of Roman or Latin status with a constitution governed by charter, which if possessing only Latin rights could be promoted to the status of a colonia.
NARROW RIDGE AND FURROW.
Long parallel soil ridges less than 5 metres across separated by furrows, formed by using a heavy plough capable of turning the soil.
OPEN SITE
Palaeolithic Open Site
A Palaeolithic or Mesolithic occupation site, excluding occupations of caves and rock shelters. Evidence for occupation may include traces of hearths and other structures.
OPPIDUM
Belgic Oppidum, Territorial Oppidum
An imprecise term used to describe large Iron Age settlements of town-like proportions.
PALISADE
An enclosure of stakes driven into the ground, sometimes for defensive purposes.
PALISADED ENCLOSURE
An enclosed settlement surrounded by a single or double row of close-set timbers embedded in a foundation trench, without ditches or banks.
PALISADED HILLTOP ENCLOSURE
A small, defended settlement dating to the Early Iron Age, located on spurs, promontories or hilltops. The defences are marked by single or double trenches which originally held substantial palisades.
PALISADED HOMESTEAD
A small, defensive settlement, usually consisting of one dwelling and ancillary buildings, surrounded by a palisade.
PALISADED SETTLEMENT
A settlement site enclosed within a timber palisade
PIT DEFINED ENCLOSURE
An enclosure where the boundary consists of a line of discrete pits, as opposed to a continuous ditch. Use with a term that describes the shape of the monument.
PLOUGH MARKS
The subsoil traces of cultivation, presumed to have been caused by the use of a plough to till the soil.
PREACHING CROSS
A cross, erected on a highway or in an open place, at which monks and others used to preach.
PROMONTORY FORT
A defensive enclosure created by constructing one or more lines of ramparts across a neck of land, in order to defend, or restrict access to, a spur or promontory, either inland or on the coast.
RAMPART
A protective earthen mound, often the main defence of a fortification.
RETENTURA
The rear part of a Roman fort, where barrack accommodation, stables and stores were situated. Use with wider site type where known.
RIDGE AND FURROW
Rig And Furrow
A series of long, raised ridges separated by ditches used to prepare the ground for arable cultivation. This was a technique, characteristic of the medieval period.
RINGWORK
A defensive bank and ditch, circular or oval in plan, surrounding one or more buildings.
RINGWORK AND BAILEY
An enclosure within a bailey which contained a keep and sometimes took the place of a motte.
ROUND
A small, Iron Age/Romano-British enclosed settlement found in South West England.
ROUND HOUSE (DOMESTIC)
Circular structure, normally indicated by one or more rings of post holes and/or a circular gulley, and usually interpreted as being of domestic function.
RUFUSE PIT
A pit where domestic waste material is deposited.
SCARP
The bank or wall immediately in front of and below the rampart.
SCOOPED SETTLEMENT
A settlement, usually enclosed, on a sloping hillside containing a number of oval or circular scopped house floors separated by walls or unexcavated ridges.
SEIGEWORK
Circumvallation, Civil War Defences, Civil War Siegework, Contravallation
A temporary earthwork or fortification constructed by forces laying siege to a castle or town, etc.
SHELL MIDDEN
A refuse heap of discarded shells.
SIGNAL STATION
A tall stone Roman tower surrounded by an enclosed courtyard and ditch. Used to watch for the approach of Saxon raiders and as a means of sending warning signals, to other stations.
SOUTERRAIN
An underground chamber, store room or passage.
STONE AVENUE
A monument consisting of parallel lines of standing stones, which appears to mark out an approach to another monument or monuments.
STORAGE PIT
A pit dug in the ground used to store meat, grain and other foodstuffs. A common feature of Iron Age farms.
STRIP LYNCHET
A terraced field usually found on hillsides. Comprising a flat strip of land, called the tread, and a steep, scarped lynchet or edge, called the riser.
TEMPORARY CAMP
Marching Camp, Practice Camp, Roman Camp.
A temporary overnight camp enclosed by a shallow ditch and palisade, constructed by Roman troops on campaigns or manoeuvres.
TIMBER AVENUE
A monument consisting of parallel lines of spaced post- holes which appears to mark out an approach to another monument or monuments.
TOFT
The place where a house stood or had once stood, often adjoining a garth or croft.
TOWN CROSS
City Cross
A cross erected within a town, usually funded by the inhabitants.
TOWN WALL
City Wall
A fortified wall surrounding a town or city.
TURRET
A small, rectangular tower, often built of stone and turf, located between milecastles along the length of Hadrian’s Wall.
UNENCLOSED HUT CIRCLE SETTLEMENT
Unenclosed Stone Hut Circle Settlement
A settlement with evidence for several hut circles but clearly lacking an obvious boundary. Where it is not certain whether a boundary existed or not, use HUT CIRCLE SETTLEMENT.
UNIVALLATE HILLFORT
Large Unlivallate Hillfort, Slight Univallate Hillfort
Characteristic of the later prehistoric period.
A hilltop enclosure bounded by a single rampart, usually accompanied by a ditch.
VALLUM
A flat bottomed ditch flanked by mounds running to the south of Hadrian’s Wall for much of its length, marking the boundary of the military zone.
VEXILATION FORT
Roman Vexillation Fortress
A military base normally between 20 and 30 acres in size, containing legionary and auxiliary battle units, which served as stores depots and winter quarters during campaigns.
VICUS
A district, suburb or quarter of a town or village adjacent to a fort, with the lowest legal status accorded to a built up area.
VILLAGE CROSS
A cross erected in a village.
WAYSIDE CROSS
A cross erected by the side of the road

Guide – Desktop

A Guide to DIY archaeology

The Desktop Search

Virtually all archaeological investigations begin with a desktop search of one form or another, the term desktop search simply means the sort of research you can do from a desk. Assuming that you have read the first section of this guide, you will already know about the basic steps of desktop research (NMR and SMR etc.), this section expands on those initial steps and introduces further avenues for deeper research, as well as discussing ways that information can be interpreted.

The Desktop Search is a range of different research avenues. For some, a comprehensive search will explore all the avenues mentioned here and more, for others, simply finding a local hill fort or tumulus on a map, and seeing it’s relationship to others is sufficient. Whatever your aim, this section aims to show the range of general search avenues available, and how they can throw new light on our understanding of the Iron Age. Since this site is aimed at the general public, our assumption will be that access to professional sources of information is difficult and will concentrate on the more accessible forms of research, at least initially. It is written in a way which attempts to get access key concepts quickly, whilst giving the amateur sufficient background information.

The archaeological investigation initially begins by gathering as much information as possible on the chosen topic, whilst applying minimal interpretation. It is important at this stage that assumptions are not made which may cause information to be disregarded. As the research continues and the information base becomes more comprehensive, elements of interpretation will be required in order to highlight further research avenues. The desktop search should not be thought of as a one off job, but an item that is subject to review throughout the research process.

The list below is not exhaustive but is indicative of the sources that should be considered for reference by those undertaking a desk-based assessment.

a.Local Sites and Monuments Record and other local databases such as those of district archaeologists;

b. national databases including the National Monuments Record, the schedule of ancient monuments, the register of historic parks and gardens, the register of battlefields and the listed building lists;

c. public and private collections of artefacts and ecofacts;

d. all Ordnance Survey maps;

e. Tithe, Enclosure Award and Parish maps and other cartographic and pictorial sources;

f. historic documents (for example, charters, registers, wills, deeds, etc) particularly those held in the Local Archives Office;

g. archaeological books and journals;

h. unpublished reports and archives (for example, local society archives, university dissertations, etc);

I. aerial photographs, particularly those held by the Local Sites and Monuments Record, the National Library of Air Photographs and the Cambridge University Committee on Aerial Photography;

j. survey of available borehole data and other geophysical and/or geotechnical information;

k. a visit to verify site conditions.

Internet Search

The most accessible means of performing research for most people is the Internet, unfortunately, when researching those lesser known sites often only a few poor quality hits are all that is available from your standard Yahoo.com or Google.com web search. However, there are a number of tricks to getting the level of detail you require for a site and increasingly the Internet is surprisingly well populated with information if you know where to look.

Keywords

The first rule, of course, with an Internet search, is to know what you are looking for! or at least, know that what you are looking for is actually available on the web. If you are new to the Internet you may not have got the hang of search keywords. The idea is to pick a set of keywords that rule out all but the most likely pages, but to also for example a search for Stanwick Iron Age Fort Brigantes on Yahoo provides a fewer number of more appropriate hits than simply Stanwick Iron Age Fort. But it may also exclude information that is also of use.

The Map Search

Roulston Scar, from Old-Maps.

There are a number of good sources of maps, online, there is www.old-maps.co.uk, which has the entire OS 1850’s series of large resolution 6 inch maps, these show up all sorts of earthworks that archaeologists are in some places just starting to pick up on, also, in general this map has the best naming of fields and given it’s age shows a significantly older landscape than is shown in modern maps. In a savage fight back of new agaist old Google Maps throw their weight behind a tunnel down set of OS maps, which ultimately go down to 1:5000 scale maps, but the best map is at 1:50,000 scale, which is based on the OS Landranger map series, the 1:25,000 map is unfortunately not based on the current Explorer series, but is instead a blow up of the 1:50,000 scale map. To make uo for this, those people at multimap have built in and air photo facility, which is best viewed at 1:25,000 scale but can give some very good shots at 1:10,000 scale or better. Just show how good multimap can be, the first site I viewed using it tonight brought up the very good view of Maiden Castle, Reeth shown below.

Maiden Castle, Reeth, from Multimap.

There are also lots of other maps available online, most of them, unfortunately, are either too general to be of real use, or are hidden deep in an elusive webpage. So it’s off to the library next, in Yorkshire, good maps started around 1610 with the John Stead Maps, these, remarkably are available in many places (including Old Mother Shiptons Cave, Knaresborough) for around £3.00, well worth looking out for. Possibly the best antiquarian map of Yorkshire is Warburtons map of 1720. Warburton took trouble to note Roman roads, many have since disappeared and in some cases are no longer recognized. For these maps plus more recent maps or older, more specific estate maps try the local library, then the county or larger libraries, if you are lucky they will allow photocopying. Other places to look include national organizations such as the Bodlian of the British Library, however access to maps without paying at this level can be very difficult and time consuming. Other maps to have to hand include the Ordnance Survey Explorer and Landranger Series, As well as their maps of Ancient and Roman Britain.

Maps – What am I looking for?

An important aspect of any ancient site is what can be seen around it. On the horizon, key features will have served as way markers for routes to other settlements and industrial, trade and religious meeting places, simply by looking at a map, a much broader picture of the environment of a particular site can be seen, often glimpses of the more ancient Iron Age can be determined, by interpreting modern indicators of activity. Recognizing the important features is a combination of several skills, which are covered in this guide.

One way of trying to understand a sites importance, is it’s relationship to sources of trade and industry – proximity to a source of natural resources or a trade route away from that site gives a settlements occupant access to both additional sources of wealth and long distance communications, in a non literate society such as that of the Celts, regular sources of good information will have been of great value, it is likely that a verbal trade was practiced, in some cases this verbal trade will have been of more value than the goods traded.

Mapping Techniques – Line of Site Analysis

Internet Research – Online Forums

Many professional and amateur archaeologists alike have become attracted to the Internet as a means of exchanging information and views. Most forums come in two guises – The email forum operates via email, with members sending mail’s to a group address, which copies the mail to everyone. The hosted forum uses a webpage which is accessed online and shows a list of discussions which may be read. Most archaeology forums are membership only, and many ban discussion on religious groups of likely to get abusive.

Newbies to the world of on-line archaeology tend to stick to chat rooms such as the Time Team Forum, or the BBC’s Talking history pages, however, discussion on these boards can often be program centric and may be of limited use. Other, more dedicated forums, such as Talking History or The Modern Antiquarian can often be a good source of information. Some forums have significant and searcheable archives, which should be consulted.

Forum etiquette

The newbie should be advised that most, if not all online forums are run by a few dedicated moderators whose function is solely to ensure things do not get out of hand. If you ask a question you should not expect an answer, and should be patient, it is a good idea to “listen in” for a while to get a feel for a forum before raising aquestion. From time to time, even the most communicative of forums seems to go to sleep, with little information getting exchanged.

Initial Interpretation

At this stage in the research, often all that is available are a few maps plus a couple of spurious mentions in other documents, however, there are ways to analyze some of the information to hand at this stage in order to confirm initial thoughts and stimulate further research without actually visiting the site. Often there are clues in the names of places. Sometimes field boundaries can be seen to continue earlier earthworks.

Place Names

Often the names of places can provide additional clues to the antiquity of a site. Names of places have originated or been modified by subsequent newcomers to Britain, but often the name itself gives away clues to even greater antiquity. For example, in Brigantia, the name Brough seems synonymous with Roman forts. Similarly the word Borough or derivatives such as Aldborough indicate a Roman presence at that location.

Studying Field-Names

Ruth E. Richardson – Council for Independent Archaeology (CIA)

Field-names may include the oldest documentary and verbal information available to us. Although most names were actually first written down in the 18th and l9th centuries, field-names are mentioned sufficiently often in manorial and estate records to show that they were in common usage. An early famous example is in the peace treaty of 1215 between King John and the barons, later known as Magna Carta, which was signed “in the meadow that is called Runnymede”, Old English for council or assembly island. In Much Marcle in Herefordshire a group of 13th and 14th century deeds has survived. They are sale transactions for the exchange of strips in the Common Fields to allow blocks of holdings to be formed. An example of a field-name on the 1839 tithe map is Normandy and this can be traced back to 1308 through these deeds. Interestingly, one deed of 1491 actually names a strip in this field, showing that at least some strips had their own independent names within the larger named field. Another example is the tithe map name of Lying Down field which can be traced back to La Lynde, or Lyndende, which shows that it is derived from the word for lime trees. Limes, even more than oaks are indicators of ancient woodland.

Field-names provide a simple and practical method for referring to a piece of land. This is only necessary if the person involved is recording information about it, or discussing it with another person. If you are working in your field you do not need to name it! It is probable that every used piece of land has, or had, a field-name because farmers, probably from as far back as the Neolithic, found this useful. A farmer could leave word of where he could be found if needed. He could easily note which fields had been worked according to agricultural requirements. The field-names chosen would be something relevant to the field. The majority concern the quality of the soil, the shape of the field, the prevalent vegetation and agricultural use. They are a way of recording difficulties about the soil and the state of the field in the days before computerised records. However, an important result of such practices was to provide a way of passing information to future generations of farmers – a stony field could break the plough – and this was especially important in the past when young adults could die suddenly.

However, for us, field-names can demonstrate changes in the landscape and they allow features to be traced. A minority of names preserves the history of the fields giving ownership names, some of which can be confirmed from other sources, or by recording significant events, which may be less easy to verify.

Two notes of caution need to be mentioned. Firstly, it is likely some fields have become subdivided. If a name was given to a particular field it is always possible that it was perpetuated attached to only a portion of the original. If the name refers to a condition like soil, or a survival like a Roman road, or indeed anything peculiar to what was once a part of a field, then it is a possibility that the name survived attached to the ‘wrong’ portion. This is why it is always useful to examine an area around a field-name and not just one modern field. Secondly, there is absolutely no certainty that each and every instance of a fieldname will have the same derivation, as some may come from other sources such as personal names. Care is needed as a lot of rubbish has discredited fieldname use in the past when people have jumped to conclusions concerning meanings. The earliest reference needs to be found if possible. Although the original spelling of a name may be difficult to determine, deductions, with a statistical probability of a meaning, can be made by examining occurrence over a wide area.

However, such reservations do not matter if a significant field- name is considered to be only the start of an investigation. It shows a site is worth examining and one needs to remember that the reason for a particular fieldname must always predate its first use for that particular field. Therefore, the age of the fieldname is crucial.

Archaeological field-names are relatively few but are an archaeological tool to be used with evidence gained from fieldwalking, geophysical surveying and aerial photography. It was in order to demonstrate their usefulness that a group of the members of the Woolhope Naturalists’ Field Club in Herefordshire decided to publish the tithe maps and the field-names for the whole county.

The tithe survey resulted from the Tithe Commutation Act of 1836 and the Herefordshire survey was produced between 1838-1846, Some counties already had enclosure maps so did not warrant a full survey. Herefordshire had few enclosure awards though the Woolhope Group used these to supplement the tithe survey where necessary. Indeed, as the field-names for every parish have now been published, Herefordshire has the first complete coverage readily available for any county in Britain. All involved were volunteers and the organization followed a set procedure, which I would be happy to describe in detail if any of you would like to ask me afterwards. Tithe maps are so large that comparing more than two is impossible. Therefore, the maps were redrawn to a uniform, and reduced, scale of 6 ins: 1 mile by a cartographer. This allows comparisons between parishes, and with ordnance survey maps, so the actual fields can be located.

Publication began in 1987 with nineteen parishes, more being added annually, usually twice a year, until all were published in the autumn of 1993.

number of people involved – 118 (collecting/publishing)

number of fields copied – 125,367

number of parishes/townships – 260, in 222 booklets

cost – from £1.25 to £4.50 per parish (total set £542)

number of booklets sold – 9,000+

They were bought by schools, libraries, the general public, the English Place-Name Society, the local Archaeological Unit and more. Requests even came from Australia, Europe and America – from people whose families used to know certain parishes. In this way more information was obtained, sometimes just about one field. In order to further publicize the potential of field-names to a wider audience the Woolhope Group entered the 1994 British Archaeological Awards and were thrilled to win. An accompanying cheque from the Robert Kiln Trust is being used as core funding for The Millennium Air Survey of Herefordshire and these aerial photographs, taken by Chris Musson, can be compared with known sites and with field-names.

The first part of The Herefordshire Field-Name Survey was simply to make the parishes, and field-names, available. The second, on- going, part is to record field-names from other sources such as wills, deeds, sales, documents, leases, etc. The information is published regularly in the Woolhope’ Club transactions. People are asked to provide the field-name found /its date /source /location using the tithe number.

This information is required whether the field-name is the same as, or different from, the tithe field-name as only in this way can the ages of the field-names be properly assessed. In addition, several of our group have analyzed particular field- names and the full results will be in the next, 1996, edition of the Woolhope Club Transactions.

Field-names provide extremely varied information about the landscape and so can be of use in many disciplines. There is still an incredible amount of information to be learned from them. Fieldnames are a direct link with the past and are an invaluable resource. It is research open to anyone and I do urge you to use them.

Using Air-photos

Jim Pickering – CIA

It is more than 70 years since archaeologists realized that photographs taken from the air provided a new source of information on archaeological sites. Information accumulated from this source is now so immense and varied that its volume is a barrier to its incorporation into the archaeological ethos both locally and nationally. Its development in Europe raises the same problems.

Initially, new archaeological information was obtained from routine air photographs taken for other than archaeological purposes. Inclusion of archaeological information was accidental. This source was made obsolete by the prospecting and recording techniques developed by the late Major Allen in the 1930s. Whilst very limited information can occasionally and unpredictably be obtained from routine photographs, the techniques of Major Allen provide the main source of new information. Unfortunately, use of the results has preceded an understanding of the factors involved.

The development of aerial archaeology as a specific subject has taken place on the periphery of archaeology rather than as an integral part of its research. To some extent this has been inevitable because training and experience are required that are not a part of archaeological studies.

Most archaeologists know that the most prolific source of new information comes from the patterns provided by small variations of growth stages of the deeper rooting annual crops, that may be visible for only a few days at infrequent annual intervals. A photograph is merely the easiest and quickest way of recording an observation. Some of the crop mark patterns are only visible from limited angles and some provide the most information from a critical angle that can only be decided by the pilot. Many casual attempts have been made by archaeologists to carry out surveys from the air, but lack of experience, perseverance and resources doomed most of them to disappointing results or total failure.

Distribution of the information obtained in this way has always been a major difficulty. Archaeological field work is mainly directed to specific sites, specific problems, specific periods and local interests. To exploit crop marks, it is necessary to carry out air archaeology in those areas where crop marks have become visible and these do not often coincide with current archaeological activity in any one year. Nor is there a sound reason to start a programme of air archaeology for an area unless it is to be systematically applied for decades. Without this, only a few known hardy annuals will be repeatedly recorded.

Interpreting the information on air photographs has made little progress in the last 50 years. The patterns of crop marks that seem similar to the ground plans of excavated sites can be plotted onto maps to provide a catalogue to information on file, but this only provides an archaeological explanation of some. It will for instance identify Roman forts, or some Roman villas, but neither excavation nor plotting on maps have explained pit alignments. There are many crop mark patterns for which there are no excavated parallels.

Guide – LOS Analysis

Line of site analysis

The purpose of using line of site analysis is to better understand the sites relationships with other locations, to identify possible trade and communications routes, and the location of other possible sites of interest, as well as providing an element of “evidence by association”. For example, a church on a possible alignment might be a good place to look for evidence of ancient remains not so far identified, and in finding such remains (of the same period) this reinforces the certainty of the alignment, indicating a communication link between these sites.

Genuine line of sight analysis is best done in conjunction with one or more site visits and thus falls a little outsite of the realm of the desktop search, however, a not insignificant contribution can be made simply by using an OS map.

To take line of sight bearings for a site, it is best to use the OS Landranger 1:50,000 map, the first task is to highlight the known interesting sites on that map sheet, I normally (since I have the luxury of two maps) mark out all ancient hill forts, settlements, river crossing points (especially those marked as old bridges), and other locations that are relevent. Where there are too many features of a particular sort (barrows for example) these are not highlighted since highlighting so many would cause the picture to become confused. It is important that this task is done several times over the course of an investigation, initially only known IA or Roman sites should be marked, other features can be marked but it is important not to have too many points to look at, this would get confusing in the early stages. It is likely that many other locations will have been settlement or meeting points, churches for example, that existed in Saxon times are very likely to have been shrines in Iron Age times, however, it should be remembered that every site has it’s own chronology which other sites may not share. As with most research, there is a limit the level of detail that can be obtained without site visits to confirm relationships suggested by desk top map work.

Having familiarised oneself with the site in relation to other sites possibly active at the time (after perhaps more research on any new sites identified other sites to establish what is known about them) a ruler can be used to see if modern tracks and boundaries line up to the line of site route suggested. If they do not, this does not mean the track did not exist, merely that this line of investigation is unlikely to yield possitive evidence. It should also be noted that alignments of sites should be expected, it is not unreasonable to assume that early settlements will have been further apart, and that those that came along later will have taken the proximity to the route into account and are more likely to have settled on a crossroads or near by, as population levels increased, people will have been forced to settle off the major routes, but this in itself may have created other routes. It is wise to bear in mind that you cannot see all that was there, so a line between two sites from the same period may have taken a detour to a third, currently unknown (at least to you) site. Similarly the natural landscape itself will have caused the track to deviate – in some cases quite massively.

One of the reasons for using a 1:50,000 scale map for this exercise is that at a higher definition, the straight line concept largely becomes obsolete without a detailed knowledge of the more local line of site markers, which are typically smaller and not noted on maps. Any alignments found and the line representing them should be treated as an indicator of the route in general. At this stage, it is not safe to actually draw in any but the most obvious ancient routes. For the later Iron Age, it is likely that many Roman roads actually follow, if not use the line of earlier routes, alignments of five or more ancient sites within a 20-30cm distance on this scale give a strong indication of an ancient route.

Above, Thornborough Henge alignment, although not straight in itself, this individual alignment, along with several other henges in the area show the route of a possible Bronze Age track, in the Iron Age this may still have been significant, the general area has wide spread evidence of Iron Age activity, and the Roman Villa at Well shows a strong indication of continued use.

Guide – Getting Started

How to research an ancient site

Introduction

The first step in researching any site, is to understand what is already known about it, many sites have had previous archaeological research, often there are air photographs or even excavation reports. Clearly it makes sense to understand as much as possible about a site before going on to any further research avenues.

General note

Unfortunately, the sources of archaeological information for a specific site are not comprehensively recorded in any one central database in the United Kingdom, so there is no single source to ask for information about a particular site. There are a number of sources which attempt to hold records centrally, however they often do not share information themselves. On top of this, in the UK there are hundreds of Archaeological and History Societies, and thousands of local groups each performing archaeological research, the vast majority of their research output is in short publishing runs and is often not recorded in any searchable format that is freely available. Finding all known information about a particular item of archaeology is therefore not an exact art, methods used in narrowing down the search can have the unwanted side effect of omitting some key evidence which usually turns up later and causes a dramatic rethink!

Clearly, with so many research avenues, there is a knack to choosing that research avenue which is most likely to turn up positive results quickly. With this in mind this section attempts to be a springboard for some of the starting blocks of research, to show some of the ways a researcher can tunnel down into as much detail on a specific site as possible.

We hope that this guide will help you find out new things about sites listed in the Brigantes Nation website, we also hope that you will pass on this information to us so the next researcher has one less task.

Central Sources

In England, the National Monuments Record (NMR) is a central record of national monuments, here you can find out what records are available (but not all), these sources can often be consulted and photocopying for private use is available at a cost. The NMR record contains aerial photographs, records of historic and listed buildings and a nationwide record of archaeological sites. Unfortunately the NMR record is not an online resource, and must be dealt with manually. Closely linked with the NMR is English Heritage, who are tasked with the care of all major archaeological sites.

For Scottish sites of interest, the National Monuments Record of Scotland (NMRS) holds the national collection of material relating to the archaeological and architectural heritage of Scotland. The sites, monuments and buildings of Scotland’s past are recorded here and made available to the public, both online and by means of exhibition and publication.

Each county or district has an archaeological curator. This person is usually based in the Planning Department of the local authority and is responsible for documenting and safeguarding the archaeology in their area. They monitor planning applications and suggest appropriate responses. These can vary from insisting on preservation to ensuring that excavations are carried out where necessary. The curator will also usually hold and maintain a record of all archaeological sites in their area, from major earthworks to single find spots. This is the Sites and Monuments Record (or SMR for short). Some SMR offices do have an online search facility.

Online NMR/SMR limited search – https://ads.ahds.ac.uk/catalogue/index.cfm

The ADS ArchSearch system has a clickable map of the UK which allows the user to tunnel down to to specific geography’s and shows the relevant SMR and NMR records for that area. This is not comprehensive, only a percentage of all SMR and NMR records are currently on this database, but it is a very good first point of access. ADS website also has a number of document libraries and some access to full online reports. It is worth taking time to get to know this site. In particular this site holds an online search system for the journal of the Society of Antiquaries, on of the main sources of early archaeological data.

Local Archaeology Sources

In general, archaeology is organized is as follows:

For known archaeology (archaeology which has been recognized and is listed locally or nationally), which is often protected, organizations or contractors will carry out fieldwork or excavation for the curator of that site. They can be single operators or small groups through to large regional or national units. All need to be approved by the Institute of Field Archaeologists (IFA). The final resting place for any finds and the notes, plans and photographs accompanying them will be an appropriate (usually local) museum. For private sites, usually of less “importance” finds and reports may be kept in private collections or museums. Often a museum, university, society or increasingly the contractor on behalf of a particular developer will publish the results of work or contents of their collection. It therefore follows that at for a particular area there can often be a myriad of potential sources of information for a particular site.

In some areas, experimental archaeology centres have been set up to allows use to learn by recreating the environment in use for a particular period. Reenactment groups contain many specialists in clothing, lifestyle and warfare.

Library Search

Many sites have been very well documented, in some cases they have had specific publications written about them, for a great many others, they are mentioned briefly in gazetteers or in more wide-ranging documents. As with all things archaeological there is not a single source to identify what has been published, sources of information include the libraries, national bodies such as English Heritage, general as well as specialist book sellers, and Archaeological Societies and Groups. Literary sources come on broadly two forms – Primary sources are those which are written first hand, such as an excavation report, secondary sources are those which are written based on primary sources, and as the name implies these are regarded as lesser sources of information. The direction a book search may take depends on the particular circumstances of the research, usually the first access point that comes to mind leads the way. Many book sellers have regular book lists, these can be particularly useful in tracking down the titles of books not found is library searches. Local libraries can often be an excellent source of historical information, often they hold journals of antiquaries whose information was based on a less developed countryside, some of these knowledgeable enthusiasts were writing at a time when their local countryside had not changed to any significant degree from Roman or Iron Age times and so had much more to see. Their interpretation is often dubious (some interpret everything as Roman) however, their descriptions of visible remains are usually spot on. Also local and libraries often collect articles and newspaper cuttings of interesting items.

Guide, Introduction

A Guide to DIY archaeology

Introduction

Background – Man’s impact on the landscape

For thousands of years men and women have fashioned the landscape according to their needs. Through the processes of farming, industrial development and related activities the successive occupying people have left their own unique mark. Initially, the geology of an area, the locally available resources such as water, drainage, defensibility, soil, as well as the relationship to other important places had a great influence on where people chose to settle. Once a place was chosen, depending on the tools available and the resources to hand, people would set about building dwellings, fields would be cleared for crops, husbandry and further settlement. In general, the more resources freely available to the settlement, the more successful it would be.

As time went by people developed both technically and into more organized social units. In time, more sophisticated social structures developed, the concept of the extended family, and the transformation of the father into leader led to more widespread tribal realms. At the same time individuals became increasingly specialized, crafts evolved which were formalized into trades. This, together with the spread of a common spiritual understanding helped people develop a social cohesion which allowed the sharing of a common cultural heritage across vast areas of Europe by the early Bronze Age (2500 BC). This increased spread of peoples, together with the power of a highly organized population, led disparate groups to come into conflict, in some cases entire populations were able to relocate and exert dominance in totally new geography’s. Towards the end of the Bronze Age, about 700 BC, helped by the exploitation of iron, a new social group emerged as dominant across a broad swathe of Europe, including England – these have been described as the Celts and were dominant throughout a great deal of Europe until the Roman at the very end of the first millennium BC. The Celts were apparently organized as tribal nations, in some cases smaller tribal units would be recognized as part of a larger tribal group. By the time of the Roman conquest of Britain, the largest tribe in Britain was known as the Brigantes, who controlled most of Yorkshire, Durham, Derbyshire, Cumbria, Lancaster and perhaps other areas as well.

The Brigantes expressed their Celtic identity in many unique and recognizable ways, and have left behind clues in the form of earthwork features and artifacts, these can be studied to reveal greater insight into the Brigantes tribe, perhaps helping us to reverse-engineer the history of the Brigantes tribe. For a better understanding of those events having impact on the Brigantes in the Late Iron Age, consult our Timeline.

The Celtic political dominance of Britain peaked and declined dramatically in the first century A.D., with the conquest by the Romans of most of the British Isles, including Brigantia. Since that time, some two thousand years have past, Britain has seen new invaders, each playing their part in the erosion and destruction of the evidence left behind by the Celts, also time itself has not been kind, wood, the most commonly used building material, has typically long since rotted, iron of course rusts and unfortunately most Iron Age pottery has hardly survived the test of time. Many sites have been built on, filled in, quarried, or are simply still lived on, however, some sites still remain, the larger sites can be very well known, such as Maiden Castle in Dorset or Mam Tor in Derbyshire but there are many, many more sites which are far less visible, many have yet to be excavated, and the exact interpretation of them can be uncertain. These remains are what we commonly call earthworks. The location and identification of these features, including hut circles, burial mounds, defensive sites, trackways, field systems and settlements has been a central theme to Iron Age archaeology for many years.

Archaeology

In many ways, the world of archaeology is an attempt to understand several worlds, in some cases thousands of years apart. Yet in order to understand a single aspect, we have to realise that each world, or period, left its footprint over those worlds that had gone before. Thus, in order to understand the world of the Iron Age, it is necessary to understand its relationship with what has had gone before, and after.

Amateur Archaeology

Like many professional disciplines, the world of archaeology has often shunned the interest of the private enthusiast, however, increasingly the role of the amateur is becoming key to the discovery of new archaeological discoveries. Archaeologists themselves are the first to agree that overall the understanding and preservation of our heritage is greatly underfunded, most funding that there is, largely goes into the preservation and recording of the known archaeological sites and materials, there is very little resource directed at identifying the thousands of ancient sites estimated to be still undiscovered. The amateur thus far has largely been an ignored and untapped resource, recent initiatives however have shown just what the amateur can achieve – Regularly metal detectorists find specific evidence which point to new areas for investigation. Local history groups and archaeology projects are for the first time allowing comprehensive field surveys and local information gathering to be performed, the resulting information is increasingly being used as part of wider archaeological research and dramatically changing our understanding of the impact the Iron Age had in shaping our countryside.

This guide attempts to show how an amateur archaeologist can make a real difference in the field of prehistoric research. It attempts to show how the myriad of research avenues available can be used simply and effectively, and how a little (or a lot!) investigation can sometimes add a great deal to our understanding of the past.

DIY Archaeology

Most people like visiting ancient sites, most people also assume that all that there is to know about a place has been written, or that what has been written tells the whole story. Every weekend thousands of us shuffle through the grand reminders of our past, many enjoy walking and find the ancient sites ideal focal points for a trip to the countryside, others visit museums thinking that the items available to view are widely known to the wider archaeological community. Yet what many do not realise, is that often there is more to these sites than has been previously noted, and that there are plenty of opportunities for the amateur archaeologist to add to the knowledge base. For example, some ploughed out earthworks can only be seen under very specific lighting conditions and are unlikely to have been shown in all but the most detailed investigations, an informed amateur could easily capture new and significant evidence. There are many other such ways that the DIY archaeologist can help out, from conducting isolated projects to participating in group activities, however, a little knowledge is a good starting point.

The biggest problem facing an amateur archaeologist is how to find out all that is already known about a particular piece of archaeology (an ancient feature or artifact). If you have a fascination for the Iron Age Brigantes Nation would like to help. It is our ambition to know all that is known about every site listed, and it is our ambition to have every known Iron Age site listed as well as any other information which helps our understanding of the Brigantes. Also, with features such as this guide, we hope to help the amateur find the best routes to information that we have yet to find.

Brigantes Nation – a quick word

Brigantes Nation was set up as an experimental project by George Chaplin in November 2001. The initial thought behind the experiment that by sharing information freely on the web, others could be encouraged to join a loose community of people with a special interest in the subjects covered. Individuals are encouraged to participate in research and also to solicit help for their own projects. The initial research project was aimed at understanding the life of Venutius, King of Brigantia (c.69AD). This has always been seen as a long term project and since then other research opportunities have presented themselves and although still primarily focussed on the Iron Age the help of contributors has enabled the number of research topics to be expanded.

This Guide

This guide is structured in a number of ways, largely in is constructed from essays on a particular subject, this way the subject gets the focus required, other sections simply give example images of artifacts to help recognition in the field, whilst others attempt to show how to make sense of the numerous types of information available.

This guide is aimed at people researching the Iron Age of Yorkshire, but addresses a much broader perspective in order to help the reader understand what evidence is relevant.

This guide, being a voluntary project, is written in order to benefit specific research, so there are some big omissions!

Celtic Warriors

Drawings of Celtic warriors as envisioned by Lucas de Heere, 1575

Though these may seem fairly accurate, more recent interpretations of how Celtic warriors looked in the late La Tène or Iron Age period before the Claudian invasions in Gaul and Britain are available. This includes depictions on coins, primarily Roman, as well as evidence from buried artifacts.

British charioteer of the Belgae and nobleman, 100 BCE

This image comes from an interesting book called Rome’s Enemies 2 Gallic and British Celts, #158 in the Men-At-Arms Series, by Peter Wilcox and Angus MacBride (ISBN: 0850456061), 1985. The paintings, done by McBride, are based on literary descriptions and archaeological finds and are said to be as accurate as possible at this time.

The Numismatics of Celtic Warriors

One of the earliest coins of the Roman Republic having a Celtic subject is a Denarius of M. Sergius Silus (116-115 BCE, Crawford 286)

The reverse alludes to his grandfather, a hero of the 2nd Punic war. Having lost his right arm in battle, he fashioned an iron arm and went on to defeat 12 enemy camps in Gaul. Note that both sword and head are held in his left hand. (Pliny)

A close up of the head shows it to be wearing a helmet similar to that on the warrior above and the coin below.

Celtic Charioteers: “In both journeys and battles, the Gauls use two-horse chariots which carry both the warrior and the charioteer.” [ Diodorus Suculus ] Since the Celts left few depictions of themselves, we are fortunate Roman coinage provides powerful images that generally confirm the written record. The 2 horse chariot (Roman ‘biga’) with six-spoked wheels seen on these 2 coins are identical to the few archaeological finds. Both coins depict a warrior, wielding a Celtic style shield and about to hurl a spear. The horses are bridled, and shown with powerful forward motion. Both warriors are naked and helmeted. The SCAURUS coin shows Bituitus, Chief of the Averni, with a spear and a typical Celtic war trumpet (carynx) with an animal shaped bell identical to those shown on the Gundestrup cauldron. L. Hostilius Saserna, denarius, (48 BCE, S312; Cr. 448/3)

Caesar, gold aureus, 48 BCE (HCRI 10)

Julius Caesar is probably best known to Celtic scholars for his description of the Gauls and Druids in his writings about the Gallic wars. This and the following two coins depict Gallic arms, trophies of war and were being used by Caesar to commemorate his victories in Gaul as well as downplaying the then current civil conflict with Pompey.

For our purposes the reverse is useful in showing us what Celtic arms looked like.

The shield is long, oval with rounded ends and is decorated.

The helmet is horned and has long ear and neck guards.

The war horn is of typical Celtic style, the bell being the head and open mouth of a fanciful animal.
The armor appears to be cloth which according to classical historians was brightly colored and patterned.
An axe is shown surmounted by a similar animal head. Though classical sources speak of spears, javelins and swords being used by Celtic warriors, the large numbers of axe heads found in Celtic territories and grave sites suggest they were almost certainly used as weapons. Caesar may have choose the axe to show since it was one of the symbols of the pontificate, and alludes to Caesar as Pontifex Maximus.

Caesar, silver denarius, 48 BCE (HCRI 11)

Caesar denarius, military mint in Spain, late 46 to early 45 BCE (HCRI 59)

For several years Caesar had been chasing Pompey’s forces around the Mediterranean with final victory in Spain. The reverses of the coins minted to pay for this campaign again celebrate his Gallic victories– propaganda for war-weary Romans. Again we see typical Gallic arms: two shields, 2 spears., an animal headed war-horn, a torque and a horned helmet. Looking closely at the battle dress, it appears to be chain or scale mail, rare among the Celts who, it is said, invented chain mail, though the torque suggests these are the Chieftain’s arms. The ‘apron’ is also decorated, perhaps studded leather or metal repoussé.

Below are 2 Gallic captives, a dejected female wearing a draped gown and a kneeling male with his hands tied behind. His pointed beard is similar to that on the next coin.

L. Hostilius Saserna, silver denarius, Rome 48 BCE (HCRI 18)

Rarely do we see portraits of actual Celts, and when done are usually idealized statuary. The following 2 coins were minted by the moneyer L. Hostilius Saserna probably under the aegis of Caesar and not the Senate.

The appearance of this portrait is much different than those of Romans, enhancing their ‘barbarian’ or foreign nature to Roman citizens. The hair is long and most likely limed, the beard and moustaches prominent and the facies peculiar. A Celtic shield is behind, and he wears a chain around his neck. This Roman has often been called Vercingetorix, most likely a Romantic notion, but then, who really knows. The reverse of this coin is the shown above.

L. Hostilius Saserna, silver denarius, Rome 48 BCE (HCRI 19)

The sister coin to the above shows a female Gaul with a typical Celtic carynx behind. She has often been called Gallia, a concept that would be absolutely foreign to the tribal Celts. More likely she represents a captive. Hear hair is long in a non-Roman fashion and almost modern in appearance, perhaps limed and forming dreadlocks. Her face is pretty in contrast to most Roman females depicted on coins.

It has been suggested that the reverse of this coin, which depicts Artemis in a Greek fashion, commemorates Caesar’s taking of Massilia which interfered with his march to Spain. Massila was an ancient Greek city and Artemis dear to her.

HCRI: Sear, DR: The History and Coinage of the Roman Imperators 49-27 BC, Spink, London, 1998, ISBN: 0907605982

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