double muscle pigs
Iron Age settlers had bring your own pig festivals (representational image)Nick Saltmarsh

Evidence of a mysterious pork festival where settlers ate only the right forelimbs of pigs has been discovered at an Iron Age site in South Wales. Scientists from the University of Cardiff found a large pile of bones at an Early Iron Age site (about 2,900 years ago) in Llanmaes, which they analysed to gain a better understanding of feasting practices in late prehistoric Britain.

Findings showed most of the bones belonged to the right forelimbs of pigs, raising questions about the social process this represented. Study authors Richard Madgwick and Jacqui Mulville argue the collapse of the Bronze Age led to a time of social upheaval, bringing about changes in cultural practices.

Their study, published in the journal Antiquity, said the evidence of these large mounds of bones suggests there was a shift away from feasts taking place for the social elite towards a more community-based event that would solidify relationships during this time of uncertainty.

Currently about 50% of the midden (the pile of cultural artefacts) at the South Wales site has been excavated. The peak accumulation period of the bones was between 750 and 400BC. The authors said that while they also came across metalwork and bronze vessels "by far the most abundant finds category was animal bone – the vast majority of which was feasting waste".

Unlike other feasting evidence, though, the Llanmaes site showed "exceptional patterns" that indicate practices in selection, processing and deposition that are "unrivalled, not only in prehistoric Britain but in any faunal assemblage known to the authors". Of the fragments recovered, 71% were from pigs. Within this, almost three quarters were of the right limb bones.

Llanmaes iron age settlement
Late Bronze Age/Early Iron Age cauldron fragments, Llanmaes, Vale of GlamorganMuseum of Wales

Madgwick said: "Surprisingly, nearly 80% of the animal remains at Llanmaes were from pigs, at a time when sheep and cattle were the main food animals and pork was not a favoured meat. What is perhaps more remarkable is that the majority of the pig bones were from just one quarter of the animal – the right forequarter."

Analysis of the bones revealed many of the pigs were not raised locally and might have been brought to the site from far away – possibly a sign that all families involved in the feast were expected to bring their own pig: "It might be that each household had to donate the same cut of meat to be included in the feast – that way everyone would have to slaughter a pig in honour of the feast. This selective pattern of feasting principally on just one quarter of one species is genuinely globally unparalleled and particularly startling as it continued over a period of centuries during the Iron Age."

As well as this feast of right forelimbs, the scientists also found butchery evidence that showed clear patterns – the carcasses were split down the middle showing "great care to divide right and left sides equally".

Because very little meat from other parts of the pig appears to have been consumed, the researchers believe festival attendees would take the remaining meat home with them. Madgwick said these controlled practices would probably have played a major role in community cohesion.

He added: "The Early Iron Age communities of South Wales and beyond would have been small and dispersed, but these feasts would have represented a time of solidarity, when people came together to feast on pig right forequarters, just as their fathers and their fathers' fathers had done."