The Great Wall of China is testimony to a mysterious culture that dominated the Eurasian steppes between 200 B.C.E. and 100 C.E. The Xiongnu, mounted warriors from what is today Mongolia, ruled from the edge of China to the grasslands of modern-day Kazakhstan and launched relentless attacks on their neighbors, prompting the wall’s construction.
The Xiongnu had no written records and left little physical evidence of their daily life. But new research published today in Science Advances combines genetics and archaeology to reveal an unusual power structure: Princesses helped build the vast, multiethnic alliances central to their centuries-long success. “Women are the active agents of empire,” says one of the authors, Bryan Miller, an archaeologist at the University of Michigan, Ann Arbor.
“It’s super exciting,” says Ursula Brosseder, an archaeologist at the University of Bonn who was not involved in the research. “They’re using genetics to explore information you cannot access with any other tool.”
Most of what we know of the Xiongnu’s history and how their society worked comes from descriptions written by their Chinese enemies. Were they a centrally controlled empire? A loose confederacy of tribes? “We had no idea what the internal structure was,” says Harvard University geneticist Christina Warinner, who co-authored the new study.
In 2007, archaeologists excavated two cemeteries from the edge of the Xiongnu empire. Located in the Altai Mountains near the border of modern-day Mongolia and China, one contained the opulent tombs of aristocrats, whereas the other was a less elaborate graveyard for local elites.
Genetic testing showed that the skeletons buried in the largest, deepest tombs with the richest grave goods such as gold discs and bronze chariot pieces were female. Their graves held sacrificed horses, sheep, and cattle, and their deep underground tombs would have been costly and time-consuming to construct.
The women buried in these palatial graves on the empire’s frontier were also closely related to people from the core of the Xiongnu empire whose DNA was analyzed in earlier research. “When you go out to the edge of the empire, it seems like women are the only ones with ties to royal lineages,” Miller says. “We’re seeing long-distance, broad scale alliances.”
Put together, the evidence suggests the Xiongnu relied on high-ranking women to knit their far-flung realm together. Xiongnu rulers likely sent their women relatives to seal alliances with local leaders. “If you want to rule a bigger area, you have to put a trusted person in place. They’re controlling local elites through these princesses,” says Bayarsaikhan Jamsranjav, an archaeologist at the Max Planck Institute of Geoanthropology and a co-author of the new study. “Genetics lets us get to the true story of the Xiongnu and its multiethnic empire.”
Artifacts found in the large tombs, meanwhile, suggest these princesses were not passive partners. They were buried with horse gear such as saddles, bridles, and bronze chariot pieces—items “associated with masculinity and power,” Warinner says, as well as critical components of the Xiongnu’s highly mobile lifestyle.
In one case, a skeleton had previously been identified as male based on its prestigious accoutrements, including horse tack and a hefty iron belt buckle. New DNA evidence revealed the skeleton was, in fact, biologically female. “Now we know men aren’t the only ones with bling,” Miller says. “Throughout their life and into death, these were important players in the community.”
The grave goods found with female burials reflected the Xiongnu’s geographic reach and control of Silk Road trade routes: finds included an Egyptian glazed ceramic bead and a Chinese lacquer cup. Even the larch wood planks of their coffins must have been imported to the treeless desert region from hundreds of kilometers away.
Men were buried in simpler graves surrounding the women’s opulent tombs. Whereas the women all shared a similar genetic background, the men were genetically diverse, Seoul National University geneticist Choongwon Jeong found by comparing their DNA to populations from across Eurasia. “The genetics cover the entirety of the steppe and its neighbors,” Jeong says, from the Caucasus Mountains to the Siberian steppe. “We have two-thirds of Eurasia represented in a single site.”
The diversity suggests the Xiongnu were deliberately mixing their population, whether through economic incentives or force, to cement control across wide stretches of the steppe, Warinner says. “We’re watching the process of empire building.”