Making Metal, Casting Society at The Cairns, Orkney

ring headed pin moulds with cast pin
Ring headed pin moulds with cast pin

New radiocarbon dates from The Cairns archaeological excavation shed light on the possible structure of society in the 3rd and 4th Centuries AD in Orkney.

Martin Carruthers, Site Director at The University of the Highlands and Islands Archaeology Institute research excavation at The Cairns, Orkney, talks about the latest research findings from the site.   

“We have been very lucky at The Cairns over the years of the excavations to find a substantial set of remains and residues that relate to Iron Age metalworking. This includes at least two iron-working furnaces, and many other features and artefacts, but there is one particularly big and concentrated event that took place beyond the broch in the northern part of the site, in the area we call Trench M. The remains of this episode include furnaces, bronze waste; bronze splashes and droplets, crucibles, and very significantly: moulds for casting fine bronze objects. Over sixty moulds and mould fragments have been recovered. These were used to cast a variety of objects ranging from simple bronze rings, to distinctive decorated dress pins, called ‘projecting ring-headed pins’, and penannular brooches, which are the lovely open-ring, cloak brooches that are sometimes referred to as ‘Celtic’ brooches.

The remains of 'Structure K' where the jewellery-making episode ocurred
The remains of structure K where the jewellery-making occurred

The volume and nature of the items being produced suggests that this was a socially significant collection of prestigious items aimed at denoting the identity, and status of those who were to wear the items; badges of their belonging and importance within the community. Importantly, it is the entire suite of materials found together, as well as their precise distribution pattern within the trench, that indicates strongly that this material relates to an in situ metalworking event, rather than a secondary event, such as merely the refuse disposal of old moulds, or even their ritual deposition. This is important because the closer we can get to the actual context of the metalworking events the clearer and more direct our picture of the process becomes.

The moulds for casting the bronze jewellery were found in an area several metres in diameter, scattered within and across the remains of an Iron Age building (Structure K) that was already ruinous and unroofed by the time the metalworking was happening. That building was itself found to overly the partially in-filled remains of a large enclosure ditch that had originally surrounded the broch period settlement. We therefore knew from the assessment of the layers (the stratigraphy) on site that the metalworking episode did not occur very early on in the sequence of events and buildings on site but it remained to be seen if it was going on towards the end of the monumental broch period on site, or if it was actually occurring after the broch was put out of use, which we know occurred around the mid-Second Century AD based on previously obtained radiocarbon dates. The calendar date of the metalworking was therefore of great interest. Did the jewellery-making episode date to the period late in the life of the broch, or was it happening after the broch itself was decommissioned and put out of use?

Two moulds for casting penannular brooches
Two moulds for casting penannular brooches

Craft and Chronology
Newly obtained radiocarbon dates make it clear which of these scenarios is correct. The new dates show that the jewellery-making occurred sometime between the AD240’s and the mid AD300’s. This places the metalworking very definitively after the end of the broch. Now, with this enhanced understanding of the chronological and structural context of the metalworking we can begin to consider the social context of this episode of metalworking. It is happening at a period of quite dramatic change in the material circumstances of Northern Iron Age communities in Scotland, at the end of the conventional Middle Iron Age and the beginning of the Later Iron Age periods, and contemporary with the mid to later Roman period further South.

It is very interesting that this episode therefore occurred after the culmination of the monumental phase of the site; after the demise of the massive broch at the heart of the community. One prominent British Iron Age scholar (Professor Niall Sharples from Cardiff University) has previously suggested that across Atlantic Scotland a pattern can be observed in which, around the time of the end of the brochs, when monumental domestic architecture is on the wane, there is a very substantial rise in the volume of items that reflect the presentation of the individual through personal adornment. This phenomenon seems to be reflected at The Cairns also.

Jewellery as social currency: Feasting, and gift-giving?
At the end of the bronze-casting event a fairly thick, very rich animal bone midden was laid down in the vicinity and slightly overlying the metalworking area. The close relationship between the metalworking and the animal bone is shown by the presence of a few of the crucibles and mould fragments amongst the midden also. What’s in this midden?

Well lots of domesticated animals, including cattle, sheep and pig, especially large cattle long bones. In addition, there were other mammal bones such as red deer, otter, and even a small quantity of horse. The midden also contained carbonised soils, ash and broken fragments of pottery. Many fire-cracked beach cobbles were also excavated, and these represent the exploded remains of ‘pot-boilers’, heated cobbles that were immersed in vessels to heat up water and cook some of the food. It seems that the people gathered at our feast were consuming beef on the bone, boiled pork, and roasted mutton and venison, some of which may have been washed down by beverages drunk from many pottery vessels.

The close stratigraphic association between the fine metalworking and the feasting raises the question of what exactly was going on here. One possibility that I like very much is that the feasting could be the spectacular social event at which the products of the jewellery-making were handed out, or gifted, to their intended recipients by those who had sponsored the metalworking in the first place. We may therefore be peering into the social circumstances of the jewellery-making and the distribution of its products amongst the community at The Cairns. If this is so, then it is a fascinating insight into the moment at which objects like the pins, brooches and rings started off on their biographies, their journey through people’s lives.

This is a very rare opportunity to see more clearly the initial nature of the social and political significance of these objects from their start-point. It would mean that the sharing or gifting of the jewellery was surrounded in the circumstances of a big social occasion, a massive party, if you like. We are seeing their birth and the important role they played in the power-play and social strategies of Iron Age groups and individuals. With the circumstances of the jewellery-making we are able, for once, to investigate the intended status and significance of these items within the context of their birth, rather than depending on the information we usually get, which is based on the discovery of these objects much later in their lives, in fact at the end of their lives, when they went in the ground, perhaps many decades, or more, after they were originally made and worn. Most theories about the brooches and pins and their role in society have been based on what we glean from them in this end-state, but the assemblage of metalworking evidence from The Cairns; the moulds, crucibles, and other items, together with the massive remains of the feasting allows us to grasp what was going on at the point in time when these jewellery items were instigated.

Jewellery, Society and the wider Northern Scottish Iron Age
It is highly intriguing that the birth of these prestigious pieces of jewellery appears to have been accompanied by communal, outdoor feasting and judging by the volume of animal bone it involved a large part, if not all, of the community. In the absence of the big spacious monumental buildings, such as the brochs, which may have previously served to gather large numbers of people under one roof at important times in the life of the community, we can ponder whether feasting events like this were the new arena for expressing the identity and solidarity of the community.

If we now recall Professor Sharples’ aforementioned thesis that the changes at the end of the Middle Iron Age to late Iron Age involved a major transformation of the way people expressed their social identity, from the communal to the individual then this evidence for big community feasting in the early part of the Later Iron Age is very interesting. Perhaps this serves to somewhat modify that concept, because in the post-broch era at The Cairns, for one, the community appears to have retained ways of expressing their greater collective identity. Nevertheless, it seems unlikely that everyone was singled-out and gifted one of the pieces of fine jewellery that were produced.

At one level, perhaps, everyone in the community was involved in the feasting, but only some were ennobled by receiving a pin; a ring, or a brooch. So it may well be that we are looking at the strategies for creating and maintaining the concept of the entire community at the same time as signalling social difference, and hierarchy within the community of this post-broch period. If so, the excavations are really coming up trumps in terms of allowing us to peer into the social circumstances of Iron Age communities.

New dates for Structure B1: Have we found the elite sponsors of the metalworking?
The period of the jewellery-making is after the end of the broch and we were previously unclear which buildings amongst the many post-broch structures were occupied at the time of the bronze-working. The new dates also allow us to pin-point whereabouts on site, at least some of, the community were living at the time the jewellery-making was taking place. Armed with the new radiocarbon dates, it turns out, that one of the large rectangular post-broch buildings (perhaps a Wag-like building of the type found in Caithness and at The Howe in Orkney) known to us as Structure B1, located about 30 metres to the south-west of the jewellery-making area was first constructed and occupied between the Mid-3rd to 4th Centuries AD, and therefore at the same time as the metalworking.

The big formal hearth in Structure B under excavation- a high status bui...
The large formal hearth in Structure B under excavation

Structure B1 lies directly over the reduced and in-filled remains of the broch. One of the most remarkable aspects of this building is its very large, formal and complex central hearth, which was over 3 metres in length in its fully developed form. This hearth and the central location of the building directly juxtaposed with the remains of the abandoned broch almost co-opting its former position and grandeur have always made us wonder if it was one of the key buildings in the immediate post-broch period at The Cairns, quite possibly the highest status building on site at that time, and may be the successor to the central broch in socio-political terms.

It is intriguing therefore to now know unambiguously that Structure B1 was contemporary with whoever was managing the wealth required to sponsor the lavish jewellery-making on site. Pushing this further, it is tempting to speculate that it was the important and powerful household resident in Structure B1 who instigated and organised the production of the jewellery, and the feasting, with all the capacity that those remarkable objects and events had for the creation and maintenance of the post-broch Iron Age community at The Cairns.”

Martin Carruthers, Site Director at The Cairns and Programme Leader for MSc Archaeological Practice, University of the Highlands and Islands Archaeology Institute.


Martin would like to thank Professor Dave Barclay, Forensic Consultant, and Professor Emeritus, Robert Gordon University Aberdeen for the very kind and helpful donation, which made it possible to fund the most recent radiocarbon dates discussed in this piece.

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