This skeleton from the early medieval site of Altheim belonged to a woman whose ancestors migrated from northern Europe several generations earlier.Credit: SAM/Harbeck
After the collapse of the Roman Empire, its northern frontier became a melting pot of soldiers, farmers and ‘barbarians’, finds an analysis of ancient genomes from hundreds of burials in southern Germany.
The populations and family practices present after the Empire’s fall in ad 476, in many ways, resemble those of modern Europe.
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The findings, published today in Nature1, rebut popular ideas of northern barbarian tribes overrunning Roman territory. Instead, they point to gradual genetic and cultural shifts that occurred through small-scale migration and intermarriage.
“That’s really important to put to bed — these romantic images of great peoples moving across the European countryside and destroying the Roman Empire,” says Patrick Geary, a medieval historian at the Institute for Advanced Study in Princeton, New Jersey, who was not involved in the study.
Ancestry patterns
The collapse of the western Roman Empire reverberated across Europe, reshaping political, religious and social systems. Ancient genomics has uncovered shifts in the genetic make-up of people in different parts of Europe during this time. But it was unclear whether these changes were due to mass migration or smaller-scale movements.
To address this, Joachim Burger, a population geneticist and anthropologist at Johannes Gutenberg University Mainz in Germany, and his colleagues focused on the Roman Empire’s northern frontier, in what is now southern Germany. They generated genome data from more than 200 individuals from distinct ‘row grave’ cemeteries that first appeared around ad 450 in small communities that cultivated the land and kept livestock.
People in the earliest burials had ancestries that are similar to ancient and present-day inhabitants of northern Germany, the Netherlands and Denmark. Burger was tempted to interpret this as evidence for the beginnings of a large-scale migration from northern Europe.
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But shared patterns of DNA suggested that this northern European ancestry predated the Roman collapse. “They haven’t arrived as mass invaders or hordes or big clans — these are individual families who are already four or five generations on Roman territory,” says Burger. They probably saw themselves as Romans, he adds.
The researchers detected a shift in ancestries after ad 470. Those buried during this period carried a mix of northern European and diverse southern European ancestries. Reconstruction of family trees from the ancient genomes suggested that people with these distinct ancestries intermarried immediately after the end of Roman rule, as social boundaries faded.
