The migrants introduced novel ritual practices to Britain, including the burial of bronze objects in the ground. The image displays a subset of the 453 artifacts discovered during the excavation of the Havering Hoard in 2018.
Researchers have revealed evidence of a significant prehistoric migration to Britain, potentially associated with the dissemination of Celtic languages. The extensive movement of people originated in continental Europe and took place from 1,400 BC to 870 BC.
The findings contribute to our understanding of the genetic composition of contemporary populations in Britain.
Approximately 50% of the ancestry in later populations in England and Wales can be traced back to these migrants.
The reasons behind the population influx during the Middle to Late Bronze Age are unclear, but it led to the introduction of new ritual practices in Britain.
Published in the peer-reviewed journal Nature, the results are based on DNA extracted from 793 ancient skeletons.
The study indicates that a gene enabling some individuals to digest raw milk experienced a rapid increase in Britain during the Iron Age—1,000 years prior to a similar occurrence in other parts of Northern Europe.
This represents an exceptional instance of natural selection for a genetic trait, and the factors driving its widespread adoption remain a mystery.
The researchers discovered four skeletons at the archaeological sites of Cliffs End Farm and Margetts Pit in Kent, indicating they were either first-generation migrants from continental Europe or their descendants.
This serves as evidence for the pioneering settlement of the region from the continent, dating as far back as 1,400 BC.
According to Dr. Thomas Booth from the Francis Crick Institute in London, individuals with the new continental ancestry initially “appear almost exclusively in Kent… but we don’t really see them anywhere else, and we don’t observe a change in the overall ancestry of Britain.”
The exceptionally well-preserved dwelling site at Must Farm in Cambridgeshire dates back to approximately the period of the migration.
However, the newly identified DNA signature rapidly disseminates: “From around 1,000 BC, suddenly that ancestry seems to disperse all the way through southern Britain, particularly,” he explained, adding, “There’s no particular genetic change in Scotland, but everywhere in England and Wales, this ancestry has an effect.”
Professor David Reich from Harvard Medical School in Boston, US, who spearheaded the research, informed BBC News: “We estimate that about half the DNA of people in the Iron Age in Britain comes from these new migrants. What that means is if you trace back the ancestors of these Iron Age Britons 20 generations before the time they lived, half of them would not be living on the island of Great Britain.”
Regarding the origin of the initial migrants in continental Europe, their closest genetic matches are with ancient populations in France. However, Professor Reich emphasizes, “We don’t yet have adequate sampling to directly confirm that or to see where exactly in France it would be.”
Upon the arrival of the newcomers, the existing British population had its roots primarily in people who came at the end of the Neolithic era, around the time when Stonehenge was under construction. These individuals belonged to the Beaker Culture.
The subsequent migration of people during the mid- to late Bronze Age introduced new cultural practices to the region. This included the deliberate burial of numerous Bronze objects, referred to as hoards, possibly as offerings to the gods.
The researchers also suggest that the migrants and their descendants in Britain played a role in the dissemination of Celtic languages.
A Late Bronze Age burial pit from Cliffs End Farm in Kent
Dr Lara Cassidy, an expert on ancient DNA from Trinity College Dublin, who was not involved with the latest study, called the findings “exciting”, adding: “It provides a potential opportunity for language change on the island.”
“Could this be the point at which the Celtic languages first enter the islands? I think the data presented here has moved the debate forward, however, it is far from conclusive.”
It’s not clear whether the migrants introduced this language group to Britain or were speaking just one type of Celtic. The branch of Celtic represented today by Irish and Scottish Gaelic – known as Goidelic – might already have been spoken by the existing inhabitants. Under this scenario, the newcomers may have spoken languages related to Welsh and Cornish – which belong to a different branch of Celtic known as Brythonic.
Co-author Prof Sir Barry Cunliffe, from the School of Archaeology at the University of Oxford, shared with BBC News, “If the Mid-Bronze Age migration had any impact on language, then the simplest hypothesis would be to see it as a vector for introducing or strengthening Brythonic.”
“If so, then Goidelic must have arrived earlier, either with the Beakers or even earlier.”
Another intriguing discovery from the new study is the rapid increase, during the Iron Age, in the frequency of a gene variant associated with lactose tolerance, allowing the digestion of raw milk.
“This trait remained rare in Britain until the middle of the Iron Age, about 2,500 years ago. It’s incredibly recent in evolutionary terms. For it to have gone from virtually non-existent to widespread in that period, the ability to digest raw milk must have had life-or-death significance,” explained Tom Booth.
“Adding to this peculiar situation is that it becomes common in Britain 1,000 years before it becomes common elsewhere in Northern Europe.”
This middle to late Bronze Age dagger was recovered from Must Farm in 1969
He further stated, “One of the leading possibilities is that Britain experienced a period of catastrophe, such as a famine or difficulties in acquiring clean water sources. Raw milk, in this context, serves as a clean source of hydration and food simultaneously. In essence, all you need are cows or sheep, and you can endure through a disaster like that.”
The mass migration to Britain occurred amid similar disruptions on the continent, contributing to a certain level of genetic homogenization among Europeans.
“In this period, there’s a convergence of ancestry throughout western and central Europe,” explained Prof Reich. “In general, although there were exceptions, northern populations became more genetically similar to southern populations, and southern populations became somewhat more genetically similar to northern populations.”
He noted that the exceptions were Scotland and the island of Sardinia, which were less affected by this North-South genetic exchange.
Dr. Cassidy emphasized the closely intertwined prehistory of Britain and Ireland, stating that it is challenging to comprehend one without considering the other. She raised a significant question prompted by this study: whether Ireland underwent a comparable scale of inward migration during or after the Middle-Late Bronze Age.
“Characterizing any differences in ancestry between Ireland and Britain during the Early Bronze Age will allow us to better understand the extent and direction of migration in subsequent periods,” she explained. Additionally, she highlighted the need to investigate if Ireland exhibits a pattern similar to Scotland, where little evidence of substantial inward migration is found following the Early Bronze Age, leading to inquiries about the introduction of the Celtic language to the island.