What Ancient Korean DNA Reveals About Society
Elite Tombs and the People Buried With Them
At the Imdang-Joyeong complex, not everyone was buried the same way. Tomb owners — the local elite for whom the graves were built — received individual burials in prominent positions. Retainers, by contrast, were sometimes grouped together in shared interments, positioned in ways consistent with sacrifice rather than natural death. Archaeologists had noticed these burial distinctions before, but the new genetic data added a layer of specificity. Researchers could now confirm biological relationships between individuals across different tomb types. Some retainers were related to each other. Some were related to tomb owners. The physical arrangement of the burials and the genetic data together painted a more complete picture of a highly stratified society in which social status was inherited, not earned.
When Entire Families Were Sacrificed
Perhaps the most striking finding in the study was the discovery of three cases in which parents and their children were sacrificed together and buried in the same grave. Historical accounts had suggested that sunjang could affect entire households, not just individual servants. The DNA data confirmed this directly. A parent and child, bound by first-degree biological relatedness, were placed together in graves associated with elite tomb owners. This means the practice was not purely transactional — selecting whichever servants happened to be available — but systematic enough to claim entire family units at once. For the researchers, this was strong evidence that retainer families may have been designated for this role across multiple generations, not just a single lifetime.
Evidence of a Sacrificial Caste
The multi-generational pattern is what led researchers to suggest the existence of a sacrificial caste: a hereditary group of families whose social role, across consecutive generations, was to be killed and buried with the ruling class. The study states directly that “genetic relatedness among sacrificial individuals over generations may suggest the presence of families that served as sacrificial individuals for the grave owner class for consecutive generations.” If accurate, this would represent a form of institutionalized, inherited servitude more rigid than ordinary slavery — one in which the obligation to die for one’s lord was passed from parent to child as a fixed social condition, embedded in the structure of Silla society itself.
Inbreeding Among Both Elites and Retainers
The researchers also found evidence of consanguineous marriage — unions between related individuals — practiced by both the Silla elite and the retainer class. Five individuals in the study, from both social tiers, had parents who were themselves closely related. One confirmed pairing involved first cousins. Consanguineous marriage was documented in Silla’s historical records, so the finding itself was not a complete surprise. What was unexpected was that the practice appeared across social classes, not just among the elite. Whether this reflected cultural norms that applied broadly, or whether retainer families had limited marriage options due to their social isolation, the study cannot determine — but the genetic signal is present in both groups.