Sex and marriage patterns in an ancient empire revealed by DNA

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Ancient DNA reveals even more secrets about the Avars, a fearsome people who built a mysterious empire that ruled much of central and eastern Europe for 250 years from the mid-sixth century.

The Avars, best known from the accounts of opponents, confused the Byzantines with formidable mounted warriors who suddenly appeared on their doorstep. The enigmatic nomads emerged en masse from the Mongolian steppe in what was one of the largest and fastest long-distance migrations in ancient history.

With lavish tombs but no written documents, the empire and its people have remained largely in the shadows of history until recently. But a groundbreaking April 2022 study using ancient DNA from the graves of the Avar elite sheds light on the empire’s distant origins.

Now a new study examining the remains of 424 people buried in four cemeteries excavated in Hungary has revealed details about the family and social life of the Avar and how the newcomers interacted with the people of their adopted homeland.

“What surprised me most was the simple fact that these people in the cemeteries are so connected,” says Zsófia Rácz, a researcher at the Institute of Archaeological Sciences of Eötvös Loránd University in Budapest, Hungary. Rácz co-authored the latest report.

The researchers were able to create detailed family trees, or family trees, the largest of which spanned nine generations over a period of two and a half centuries. The team found that about 300 of the individuals had a close relative buried in the same cemetery.

The analysis found that men remained in their community after marriage, while women married outside their original community – a pattern known as patrilocality.

“We cannot find the parents of all mothers. The parents are not on site. While all males are descendants of the founders,” says Guido Alberto Gnecchi-Ruscone, lead author of the study published on Wednesday in the journal Nature.

Research into mitochondrial DNA, which reveals the female lineage, showed great variability, suggesting that the women who married into the Avar groups came from different places, said Gnecchi-Ruscone, a postdoctoral researcher in archaeogenetics at the Max Planck Institute for Evolutionary Anthropology. in Leipzig, Germany. They still shared a ‘steppe’ genetic ancestry, indicating that they were probably not conquered locals.

Multiple partners in patriarchal clans

Furthermore, the study found that it was relatively common for both men and women in Avar society to have children with multiple partners.

Among men, researchers found two partners in ten cases, three partners in four cases and four partners in one case. Having multiple wives may have been relatively common in both the general population and the elite, the study authors wrote.

The team also discovered several cases of closely related male individuals having offspring with the same female partner: three pairs of fathers and sons, two pairs of full brothers and a sibling of paternal half-brothers, and an uncle and cousin.

Similar ‘levirate associations’ that took place after the death of the woman’s husband existed in other Eurasian steppe communities, according to the research, suggesting that the Avars, who abandoned their nomadic way of life based on herding, became more settled shortly after their arrival in Europe they continued to cling to some aspects of their previous way of life.

Lara Cassidy, a geneticist and assistant professor at Trinity College Dublin who was not involved in the new research, said the authors had “deftly unraveled” the organizing principles of this medieval society and provided “compelling evidence for a rigid patrilineal system , in which children belong to their father’s family and their ancestors go back from father to son.”

In a commentary published alongside the study, she largely agreed with the authors’ statement for multiple reproductive partners.

“Polygamy (having multiple spouses), serial monogamous marriages and extramarital affairs are all possible explanations,” she said.

“However, two cases of men with multiple older female partners, all middle-aged at death, provide a good argument for polygyny. In contrast, most cases of women with multiple partners were apparent levirate unions, in which a widow would marry the son or brother of the deceased. This is a common practice among pastoralists… both caring for widows and requiring them to honor marriage contracts conditional on their having male heirs.”

Close-knit family groups

Gnecchi-Ruscone said the biological continuity in the close-knit population the researchers studied was striking, especially given that there was no sign of interbreeding between close blood relatives – a phenomenon known as consanguinity.

“Even more distant crosses such as (between) cousins ​​or second cousins ​​leave genetic traces. And we see absolutely no blood relationship among these individuals,” he said.

“This really tells us that they knew who their biological relatives were, and that they traced their biological relatives through the generations.”

It was not possible to understand the community’s gender-power dynamics using only the study of ancient DNA, Gnecchi-Ruscone said.

Men’s burials were more likely to include high-status grave goods such as horses, saddles and armor, Rácz said. However, women have likely played a role in promoting social cohesion by connecting individual communities.

Cassidy said the oral history of female line genealogy may have been important to the Avars, ensuring that daughters did not take husbands from their mothers’ or grandmothers’ relatives.

Avalanche graves – around 100,000 have been excavated to date – are an important part of Europe’s archaeological heritage.

The Avars were once part of what the Chinese called the Rouran Khaganate or confederation of tribes, which defeated the Turks in 550, forcing the Avars to flee westward.

According to the 2022 study published in the journal Cell, which mapped the group’s Asian origins, the Avars traveled more than 5,000 kilometers (3,100 miles) from Mongolia to the Caucasus in a few years. They set up a base in what is now Hungary and came close to Constantinople, the center of the Byzantine Empire, being crushed.

Some historians say the Avars brought the stirrup to Europe – a transformative technology that made warfare possible and was subsequently widely adopted across the continent.

The research was a “fruitful interweaving of genetics, history and archaeology,” said Bryan Miller, assistant professor of Central Asian art and archeology at the University of Michigan, who was not involved in the study.

“Many previous studies have claimed to cover all of Eurasia with a broad population, relying on one individual per community or a handful of individuals to represent an entire culture or society,” he said via email.

“Instead, this study shows how only a much higher resolution dataset, with fuller examination of entire communities, can provide the kind of definitive or nuanced stories that the previous big data studies sought to provide.”

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