Heavy Metal in the Iron AgeFor the Celtic peoples of Iron Age Europe, metalworking was an extremely important craft. From the weapons they used in battle, to domestic items such as cauldrons, jewellery and mirrors, to chariot fittings, coins and agricultural tools, metals such as iron, bronze, silver and gold played a central part in Iron Age society.

This exhibition looks at various uses of metals in Iron Age East Yorkshire. We tell the story of the discovery and conserva-tion of the South Cave Weapons Cache, a unique example of prestige metalwork. Dr. Peter Halkon of the University of Hull looks at iron production in the Foulness Valley area, from where the iron to make the South Cave weapons probably came. The exhibition also features a variety of Iron Age artefacts discovered through metal detecting in the East Riding. Finally, we take a look back at the education programme that has gone on as part of the project.

AcknowledgementsWe would particularly like to thank the following for their assistance in this display

The Museum of London Archaeology ServiceRS Displays & Exhibitions Ltd.Dr. Peter Halkon, University of HullYork Archaeological TrustKingston-upon-Hull City Council Museums & Art GalleriesHumber Archaeology PartnershipThe late Terry BrittenMick CarrJack CooperTerence DouglasChris HannardJeff LyonsDon WaudbyOther members of the metal detecting community

DiscoveryThe South Cave Weapons Cache was found in September 2002, by metal detectorists Mick Carr, Patrick Walby and John Connell, on farming land at South Cave, East Yorkshire.

The cache includes five iron swords, contained within copper alloy scabbards and 33 iron spearheads, each of a different shape and size.

Initially just one scabbard tip was recovered, but later, two swords and some Roman pottery were uncovered. Realising the importance of the site, the metal detecting society contacted the Humber Archaeological Partnership, who along with conservators from the York Archaeological Trust, carried out the excavation and recording of the cache.

PurchaseFollowing a detailed assessment of the finds and some initial conservation by HAP/YAT, issues of ownership had to be resolved. Eventually, East Riding of Yorkshire Council was successful in an application to the Heritage Lottery Fund to purchase, conserve, display and publish the finds. The total project cost was £174,000, of which 75% came from HLF and the rest from the Council. The conservation and analysis of the cache was carried out by the Museum of London Archaeology Service. (MOLAS)

The burialEach scabbard has distinct decoration. The sword handles were made from a mixture of metal and organic materials. The weapons were tightly packed together in a shallow

pit and were probably originally tied together. Spear shafts had been carefully removed and the heads wrapped in an organic material. The whole cache was covered with pieces of Roman amphora (storage jars).

SignificanceAlthough ploughing has damaged two of the scabbards, the objects are in remarkably good condition. Iron Age weapons are always rare finds, so a discovery of this kind is of international importance for the study of Iron Age weaponry and metalwork. The cache is thought to have been buried in about 70AD, about the time of the Roman conquest of this area. The reason for the burial is not known – an after battle ritual or a secret arms dump for the local Parisi tribe are just two possible explanations.

The South Cave Weapons Cache

Cleaning around the weapons (Copyright York Archaeological Trust)

General view of the cache as excavation progresses (Copyright YAT)

The discovery of the cache soon attracted many visitors from the archaeological world (Copyright YAT)

The scabbard tip that started the whole story (Copyright YAT)

After recording the cache is removed to the conservation laboratory (Copyright YAT)

The delicate task continues (Copyright Mick Carr)

Excavation in progress, amphora sherds and swords emerging (Copyright YAT)

Excavation in progress, September 2002 (Copyright Mick Carr)

Work began on conserving the cache immediately after the rescue excavation in September 2002. York Archaeological Trust (YAT) did this vital work. Two of the swords had suffered plough damage. Sword 16 had its decorative chape ripped off the end. Sword 17 was bent almost at a right angle and the scabbard split open for much of its length. In general, the copper alloy scabbards were in good shape, although some decorative inlays were missing. The visible parts of the iron swords and the spearheads were clearly in a fragile state and very unstable. All five swords were corroded such that removal from

their scabbards might prove difficult. The spearheads were rusted together in a bundle, making it impossible even to count them, let alone see any details.Initial work was carried out to identify and catalogue the finds and stabilise them for short-term storage. Fortunately, English Heritage provided a grant to enable a detailed assessment report to be produced by Humber Archaeology Partnership (HAP) and YAT. This was not simply a catalogue of the finds, but also looked at the site itself, the importance of the finds and recommendations for future treatment.

The conservation process included x-raying the finds. Unpicking the bundle of spearheads revealed there were 33 in all. This painstaking work meant that even the smallest pieces were preserved for future study.

Finally, purpose built packaging was produced, so that the cache could be stored in environmentally stable conditions until the necessary funds could be raised for full conservation.

Conservation & Analysis I :Post excavation

Plough damage to sword 17 (Copy-right ERYC)

The corroded bundle of spearheads numbered before work on separation begins (Copyright York Archaeological Trust)

Suspension loop on rear of a scabbard, filled with soil (Copyright ERYC)

Scabbard of sword 17 showing damage (Copyright ERYC)

The spearheads in their purpose-made packaging after initial conservation (Copyright YAT)

Brushing away loose soil and corrosion (Copyright YAT)

Following the successful bid to the Heritage Lottery Fund in 2005, £33,000 became available for the conservation of the weapons up to display standard, £8000 for specialist analysis and £1500 for digital photography of the finds. The Museum of London Archaeology Service (MOLAS) was awarded the tender for this work. The following three panels look at some of this process.

Aims• To ensure the finds are preserved for the long-term. This

included involving the conservation team with the design of the display case, as this would be critical for the future survival of the finds.

• To achieve a level of conservation at which the finds could be displayed to the best possible visual effect

• To carry out detailed analysis of the metalwork, organics and other materials, looking at how the weapons were made, and also researching other similar finds.

The above aims are not without problems. For example, in trying to achieve an attractive display, valuable historical evidence might be lost or irreversible damage might be caused to the finds. It is a generally accepted principle that conservation techniques should be reversible, but this is not always possible. Ethics also come into the equation…

Some difficult questionsWhy not unbend the swords?This would probably cause much damage to the two swords concerned and could not be justified ethically. The plough damage is part of the history of the cache. The swords were therefore conserved in their current shapes.

How about separating the swords from the scabbards?The project team carefully considered this option. Because the cache swords have iron blades inside

copper alloy scabbards, there is always the possibility that decay of the former might split and damage the latter. Some additional information might be gained by separation – possibly the blades might be decorated or have maker’s marks on them. However, x-rays do not show any evidence for this. There is also an argument that the separate elements would be easier to preserve – but no conservation process can be guaranteed. Separation might make for a better display in some cases, but here the iron is generally poorly preserved. Ultimately, the project team decided that separation was not in the best interests of the objects. The likelihood of damage to the swords, the current stability of their condition and the doubtful ethics of such an action were felt to outweigh any likely benefits.

Conservation & Analysis II

Reverse of swords 40 & 41 before MOLAS conservation

Sword 40 before MOLAS conservation (Copyright ERYC/MOLAS)

Decoration on sword 16 before MOLAS conservation (Copyright ERYC/MOLAS)

Sword 41 before MOLAS conservation (Copyright ERYC/MOLAS)

Spearhead 18 before MOLAS conservation (Copyright ERYC/MOLAS)

Spearhead 14 before MOLAS conservation (Copyright ERYC/MOLAS)

Sword 18 before MOLAS conservation (Copyright ERYC/MOLAS)

Some more tricky issuesHow much cleaning should we do?Some of the sword scabbards when cleaned up displayed large areas of the original metal surface – quite incredible after nearly 2000 years in the ground. But, there were areas of minerally preserved organic material. Should they be removed to make the items more attractive when on display? It was decided to retain these until analysis could be done.

Should reconstruction be done?Full reconstruction of the finds was not thought to be possible or ethical, due to the fragmentary nature of the sword hilts. Not all pieces could be accurately fitted back together and the use of adhesives might compromise future analysis work. Where possible, joining pieces were identified and the swords display reflects this work. Restoration of missing elements was not attempted.

TechniquesConservation can be both investigative i.e. finding out about how the objects were made and the materials used and preservative, i.e. keeping the objects stable by

preventing further decay and strengthening them. The amount of work done depends on available budget, the importance of the finds and their intended use. With the weapons cache, since the finds were highly important and destined for permanent display, conservation work was very complex.

X-rays were used to act as a guide to cleaning and to reveal any hidden decoration or other features not visible to the naked eye.

This was followed by manual cleaning with small hand tools e.g. scalpels and soft brushes which is carried out with the aid of high-powered microscopes, cotton wool swabs and industrial methylated spirit. This is the best method of removing the mixture of soil and “bronze disease” (green corrosion) on the swords, since you can pause at any time in the process.

Mechanical cleaning with powered tools such as compressed air blowers and mini drills is useful for removing harder layers of corrosion and hopefully revealing the original shape of the objects. But it can damage finds if not carefully applied. Compressed air was used to fire tiny amounts of aluminium oxide at the weapons, in order to clean the surface. This was carried out inside containers called “glove boxes”, which protect

the conservator from flying particles.

Chemical cleaningIn the past, this was often used to strip objects down to their metal core. This is not only dangerous because of the chemicals used, but it can also be difficult to distinguish corrosion from the actual surface of the object. Irreparable damage can be caused. Chemical cleaning was not undertaken in this case.

AdhesivesWhere joins could be identified, broken parts have been reattached, using adhesives that can be reversed in the future if necessary.

Final stagesThe surfaces of the artefacts were degreased to remove any finger marks. The remains of the iron sword blades were lacquered to consolidate them, as they are very fragile.

Conservation & Analysis III

Manual cleaning of a cache sword in progress (Copyright MOLAS)

X-ray of two of the cache swords (Copyright YAT)

X ray of some of the cache spearheads (Copyright YAT)

Cleaning a decorative panel (Copyright ERYC/MOLAS)

Mechanical cleaning of a spearhead inside a glove box (Copyright ERYC/MOLAS)

YAT staff preparing spearheads for x-rays (Copyright York Archaeological Trust)

IllustrationsDigital photographs have been taken at all stages of the conservation process. This acts not only as a record of the project, but also allowed specialists to work from the photographs, reducing the amount of handling of these unique objects.

Each sword and spearhead has been drawn, in preparation for the publication of the cache in an archaeological journal.

ResearchResearch was carried out to look for parallels with finds of Iron Age swords elsewhere in Britain. The decorative parts of the sword handles were particularly important for this work. A sword handle and hilt guard from Warton,

Lancashire (now in the British Museum) is a close match for pommel, handle and hilt pieces from South Cave sword RF17. However, the Warton sword has copper alloy fittings over an iron tang - the South Cave sword has the same parts in bone or ivory. It is unclear which (if either) is imitating the other and which materials would have been considered of higher status. Unfortunately, the Warton sword cannot be closely dated.

Specialist reports on the different materials were produced. Full details will be included in the final publication; only a few key facts are presented here

The swords The South Cave swords have several combinations of materials. For example, Sword 16 has a whale ivory hilt guard and a pommel carved from the same material. The grip may have been made of elephant ivory.

Sword 17 has a whale ivory grip and an elephant ivory hilt guard.Sword 18 has the remains of a whale ivory pommel and an antler grip.Sword 40 has a horn grip (probably cattle horn).

The elephant ivory points to trade with the Romans and could have come from Africa or India. It is definitely not mammoth ivory. The whale ivory was probably obtained from sperm whale teeth. This could be the result of hunting, but may have come from a dead whale washed up on a beach. Overall, the South Cave swords are remarkable for the range and combination of materials used in their hilts, but there is not enough evidence to say whether they are typical or not. Parallels are mostly with finds from the north of Britain e.g. Rudston, Kirkburn and Warton. The South Cave swords seem to be within the tradition of Iron Age swords from this region.

A CT scan of sword 40 did not show any evidence for maker’s marks or any decoration on the iron blade. The cross section of the blade was a simple elliptical shape.

SpearheadsThe spearheads were probably wrapped in an animal skin before burial.

Most of them were buried without their wooden shafts, but a few show traces of wood in the sockets. The species of wood could not be identified.

Conservation & Analysis IV

Closeup of sword 17 (Copyright ERYC)

Sword 41 after conservation (Copyright ERYC/MOLAS)

Sword 18 after conservation (Copyright ERYC/MOLAS)

Rear face of scabbard showing exceptional preservation of metalwork (Copyright ERYC/MOLAS)

Spearhead after conservation (Copyright ERYC/MOLAS)

X-ray showing construction details of the scabbards (Copyright York Archaeological Trust)

The South Cave weapons cache was found on the edge of the Foulness Valley near the western edge of the Yorkshire Wolds, overlooking the Walling Fen tidal inlet. The area had an extensive network of creeks, connecting to the Humber. Log boats have been found at Hasholme and Newport, near to iron production centres.

Plant and insect remains show that the landscape around the inlet was heavily wooded – charcoal was an essential element in the iron smelting process. By the late Iron Age, the sandy ridges overlooking the wetlands between Market Weighton and the Humber were cleared and densely occupied.

Iron Production in East YorkshireThe Foulness (pronounced “Foona”) river, meaning “dirty river”, probably owes its name to the presence of bog iron ore, giving the water a rusty colour. Its ores have been

successfully smelted in experimental furnaces. The earliest iron objects from East Yorkshire are pins from the fortified hilltop site of Staple Howe, but most of the evidence comes from the “Arras culture” period (c. 400 – 100 BC). This is named after Arras near Market Weighton, where burials surrounded by small square enclosures were excavated, some containing dismantled chariots. These are similar to burials in northern France. New methods of iron production may have been introduced from the continent at the same time.

In 1985 a heap of iron slag weighing 5,538 kg was excavated at Welham Bridge. It probably dates to between 400-200BC. Eighteen other iron-smelting sites were found in a small area around Holme-on-Spalding-Moor, making it an iron production centre of considerable importance. The heap would have produced 800 sword shaped bars of trade iron. Experimental archaeology has shown that an iron tyre weighing 4 kg would have needed 700 kg of charcoal, itself the product of 5 tonnes of wood and c. 130 person days of labour.

Craftsmen in metal The evidence for iron production and bronze working at various sites in the Hull Valley and Foulness Valley makes it likely that the swords and spears of the South Cave weapons cache were made in this region.

Little is known of the people who carried out these processes. Blacksmith’s tools, including tongs and two “pokers” were deposited in a former grain storage pit at Garton Slack. At Rudston a pair of blacksmith’s tongs and a hammer was found in the grave of a male aged around 20, which also contained a short sword and two spearheads. Possible craftsman burials are rare in Britain and include an example from Whitcombe, Dorset.

Valley of the First Iron Masters– metalworking in the landscape of Iron Age East Yorkshire

Metalworking in the East Yorkshire landscape (copyright Peter Halkon/Helen Fenwick)

The Hasholme log boat, discovered in 1984 (Copyright M. Millett)

The Welham Bridge slag heap being excavated (Copyright Peter Halkon)

Part of the Arras cemetery from the air (Copyright Peter Halkon)

The Kirkburn chariot burial under excavation, including a chain mail shirt (Copyright Peter Halkon)

Experimental iron smelting furnace and artist’s reconstruction (Copyright Peter Halkon/Mark Faulkner, courtesy of Peter Crew)

The Elmswell plaque, 1stc AD. Probably a box mount, showing mixture of Celtic and Roman style decoration. (Copyright Peter Halkon)

East Yorkshire, probably the territory of the Parisi tribe, saw major changes in the 1st century BC / 1st century AD. Square barrow burial may have ceased and there was an influx of coins from the Corieltauvi tribe to the south of the Humber. Wheel thrown pottery came into the re-gion for the first time, similar to vessels from Dragonby in North Lincolnshire.

The Romans arriveIn AD 43 the Romans invaded Britain and by the 50s AD they had reached south and west Yorkshire and the Hum-ber bank. A trading centre was created at Redcliff, North Ferriby perhaps as a centre for the exchange of new styles of brooches and pottery from the conquered south and the continent.

Around AD71, the Roman army crossed into the territory of the Parisi as part of the campaign against the Brigantes

to the north and west, who had rebelled against Rome. It has been presumed that the Parisi too were at first pro-Roman. We will probably never know why the South Cave Weapons Cache was buried. It may show, along with the building of Roman forts at Hayton, Brough, and possi-bly at Malton, Stamford Bridge and Buttercrambe, that not all of the Parisi were peacefully inclined. The weapons may have belonged to a war band of some kind.

Why was the cache buried?Roman law forbade the carrying of arms by civilians. Possibly the cache was deposited in a ritual act marking the end of an era. It was buried near a group of springs. The placing of offerings close to or in water is common at this time. The hilltop enclosure overlooking the site, perhaps dating from the early Iron Age, may also have had ritual associations.

The cache was placed in a pit cut into a settlement ditch containing Roman style pottery and “hidden” by pieces of an amphora from Spain. This may show that elements of Roman lifestyle had been adopted. However, that they were hidden at all, suggests that someone may have intended to recover the weapons.

A landscape of change

The landscape of the South Cave Weapons cache (Copyright Peter Hal-kon)

Smithing an iron bloom smelted in an experimental furnace (copyright Peter Halkon)

A Dragonby style wheel-thrown pottery bowl from Bursea (Copyright Peter Halkon)

Hayton Roman fort showing as crop marks from the air (Copyright Peter Halkon)

From the beginning of the project in September 2005, until its completion in 2008, the following educational activities have taken place:

- Six public lectures, covering topics such as chariot burials, iron working, recreating Iron Age costume and the conservation of the cache.- Three workshops for children, including “Meet The

Celts” and flint knapping.- Five workshops for adults looking at Iron Age blacksmithing, textiles, chalk carving, pottery making and building round houses.- A “Celtic life day”, featuring historical re-enactment group the Parisi and Hollywood sword maker Magnus Sigurdsson, along with model round house, chariot and pottery making for children.

- A full-sized replica sword and scabbard based on one of the swords from the cache- An Iron Age pottery “puzzle”- Replica Iron Age clothing for use by visiting school groups- School loan boxes themed around the Iron Age

South Cave Weapons cache:The Education programme

Close-up of the ironworking furnaceCompleted section of the round house

Chalk carving workshop, the Treasure House

Weapons demonstration, Celtic Life Day at the Treasure House

Members of the Parisi at Celtic Life Day

Pottery interactive, The Treasure House (All images on this panel copyright East Riding of Yorkshire Council)

Craft tools display, Celtic Life Day

Round house construction at Skidby Windmill

David Freeman demonstrating use of bellows with an iron working furnace, during a workshop at Skidby Windmill

Weaving demonstration, Celtic Life Day

Two members of Legion IX Hispana, Celtic Life Day

Celtic Life Day

The images here show the progress of the South Cave Weapons Cache from its discovery in 2002 until the completion of the conservation. Then go to Gallery 1 to see these outstanding finds.

From excavation to display

(Copyright YAT)

(Copyright YAT) (Copyright Mick Carr) (Copyright YAT) (Copyright YAT)

(Copyright YAT) (Copyright ERYC/MOLAS) (Copyright ERYC/MOLAS)

(Copyright ERYC/MOLAS)