The First Nomadic Empire of Mongolia Revealed by Ancient DNA with a Multiethnic Structure

April 14, 2023

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The Xiongnu, the first nomadic empire in the world, has been hiding in the shadows of history for centuries. But thanks to meticulous archaeological excavations and new ancient DNA evidence, the empire that rose on the Mongolian steppe 1,500 years before the Mongols is finally coming into view. The Xiongnu empire was one of the most potent political forces in Iron Age Asia, and it had stretched its reach and influence from Egypt to Rome to Imperial China.

The Xiongnu's economy was based on animal husbandry and dairying, and they were well-known for their nomadic lifestyle, relying on horses to build their empire. Their proficiency in mounted warfare made them formidable foes, and their legendary conflicts with Imperial China contributed to the construction of the Great Wall. However, the Xiongnu did not develop a writing system, and historical records about them were written and passed down by their rivals and enemies, offering little insight into their origins, political rise, or social organization.

Recent archaeogenetics studies have traced the Xiongnu's origins as a political entity to a sudden migration and mixing of various nomadic groups in northern Mongolia around 200 BCE. However, such findings have produced more questions than answers. To gain a better understanding of the Xiongnu empire's inner workings, an international team of researchers from the Max Planck Institutes for Evolutionary Anthropology (MPI-EVA) and Geoanthropology (MPI-GEO), Seoul National University, the University of Michigan, and Harvard University conducted an in-depth genetic investigation of two imperial elite Xiongnu cemeteries along the western frontier of the empire: an aristocratic elite cemetery at Takhiltyn Khotgor and a local elite cemetery at Shombuuzyn Belchir. The research has been published in the journal Science Advances.

'We knew that the Xiongnu had a high degree of genetic diversity, but due to a lack of community-scale genomic data, it remained unclear whether this diversity emerged from a heterogeneous patchwork of locally homogenous communities or whether local communities were themselves genetically diverse,' explains Juhyeon Lee, the first author of the study and a Ph.D. student at Seoul National University. 'We wanted to know how such genetic diversity was structured at different social and political scales, as well as in relation to power, wealth, and gender.'

Researchers found that individuals within the two cemeteries exhibited extremely high genetic diversity, to a degree comparable to that found across the Xiongnu Empire as a whole. High genetic diversity and heterogeneity were present at all levels – across the empire, within individual communities, and even within individual families – confirming the characterization of the Xiongnu Empire as a multiethnic empire. However, much of this diversity was stratified by status.

The lowest status individuals (interred as satellite burials of the elites, likely reflecting a servant status) exhibited the highest genetic diversity and heterogeneity, suggesting that these individuals originated from far-flung parts of the Xiongnu Empire or beyond. In contrast, local and aristocratic elites buried in wood-plank coffins within square tombs and stone ring graves exhibited lower overall genetic diversity and harbored higher proportions of eastern Eurasian ancestries. This suggests that elite status and power were concentrated among specific genetic subsets of the broader Xiongnu population. Nevertheless, even elite families appear to have leveraged marriage to cement ties to the newly incorporated groups, especially at Shombuuzyn Belchir.

'We now have a better idea of how the Xiongnu expanded their empire by incorporating disparate groups and leveraging marriage and kinship into empire building,' explains senior author Dr. Choongwon Jeong, an Associate Professor of Biological Sciences at Seoul National University.

The study's second major finding was that high-status Xiongnu burials and elite grave goods were disproportionately associated with women, corroborating textual and archaeological evidence that Xiongnu women played prominent political roles in expanding and integrating new territories along the empire's frontier.

At the aristocratic elite cemetery of Takhiltyn Khotgor, researchers found that the elite monumental tombs had been built for women, with each prominent woman flanked by a host of commoner males buried in simple graves. The women were interred in elaborate coffins with the golden sun and moon emblems of Xiongnu imperial power and one tomb even contained a team of six horses and a partial chariot.

At the nearby local elite cemetery of Shombuuzyn Belchir, women likewise occupied the wealthiest and most elaborate graves, with grave goods consisting of wooden coffins, golden emblems and gilded objects, glass and faience beads, Chinese mirrors, a bronze cauldron, silk clothing, wooden carts, and more than a dozen livestock, as well as three objects conventionally associated with male horse-mounted warriors: a Chinese lacquer cup, a gilded iron belt clasp, and horse tack. Such objects and their symbolism convey the great political power of the women.

'Women held great power as agents of the Xiongnu imperial state along the frontier, often holding exclusive noble ranks, maintaining Xiongnu traditions, and engaging in both steppe power politics and the so-called Silk Road networks of exchange,' says Dr. Bryan Miller, project archaeologist and Assistant Professor of Central Asian Art & Archaeology at the University of Michigan.

Genetic analysis also provided rare insights into the social roles of children in Xiongnu society. 'Children received differential mortuary treatment depending upon age and sex, giving clues to the ages at which gender and status were ascribed in Xiongnu society,' says senior author Dr. Christina Warinner, Associate Professor of Anthropology at Harvard University and Group Leader at the Max Planck Institute for Evolutionary Anthropology.

Researchers found, for example, that although adolescent Xiongnu boys as young as 11–12 years old were buried with a bow and arrows, in a manner resembling that of adult males, younger boys were not. This suggests that the gendered social roles of hunter and warrior were not ascribed to boys until late childhood or early adolescence.

Although the Xiongnu empire ultimately disintegrated in the late 1st century CE, the findings of the study point to the enduring social and cultural legacy of the Xiongnu.

'Our results confirm the long-standing nomadic tradition of elite princesses playing critical roles in the political and economic life of the empires, especially in periphery regions—a tradition that began with the Xiongnu and continued more than a thousand years later under the Mongol Empire,' says Dr. Jamsranjav Bayarsaikhan, project archaeologist and Mongolian Archaeology Project: Surveying the Steppes (MAPSS) project coordinator at the Max Planck Institute for Geoanthropology. 'While history has at times dismissed nomadic empires as fragile and short, their strong traditions have never been broken.'

Journal information: Science Advances

Provided by Max Planck Society