Silla Society in the Three Kingdoms Era Was a Dense Kinship Network... First Genetic Evidence of Cousin Marriage and Sacrificial Class [Reading Science]

Analysis of 78 Individuals from the Imdang-Joyeong Tomb Cluster Reveals Dense First, Second, and Third-Degree Kinship Networks
Principal Tomb Occupants and Sacrificial Individuals Share Genetic Backgrounds but Are Separated by Kinship Ties

For the first time, ancient DNA analysis has confirmed that Silla society during the Three Kingdoms period operated on a far denser network of kinship ties than previously thought. The practice of cousin marriage, historically known only from written records, and the structural separation of the sacrificial class, have now been genetically substantiated. This provides new clues for interpreting the kinship order and funerary culture of ancient Korean society.

Reference photo to aid understanding of the article. Excavation site of the 'Bihwa Gaya Ruler's Tomb' at Gyesung Burial Mounds in Changnyeong, Gyeongnam. Photo by The Asia Business Daily Database

A joint research team from Yeungnam University, Seoul National University, Sejong University, and the Max Planck Institute in Germany published their findings on April 9, 2026, in Science Advances, after analyzing the whole genomes of 78 ancient human remains unearthed from the Imdang-Joyeong tomb cluster in Gyeongsan, North Gyeongsang Province. The team reconstructed the genetic relationships between principal tomb occupants and sacrificial individuals from 44 tombs constructed over approximately 100 years during the 4th to 6th centuries, tracing the kinship structure of the local society at that time.

The analysis confirmed 11 pairs of first-degree relatives, 23 pairs of second-degree relatives, and 20 pairs of third-degree or more distant relatives. The results indicate that a tightly knit kinship network extended over multiple generations around certain tomb clusters. Notably, five individuals were found whose parents were close relatives, providing direct genetic evidence for the cousin marriage customs of Silla described in historical records such as the Samguk Sagi.

Cousin Marriage in Historical Records, Now Found in Silla Bones

The most significant aspect of this study is that it empirically demonstrates, using ancient genomes, the marriage practices of Silla previously known only from historical documents. The research team identified long, identical stretches of DNA inherited from both parents—so-called runs of homozygosity (ROH)—in certain female individuals. This indicates that their parents were cousins or even more closely related, suggesting that cousin marriage, previously believed to be exclusive to royal elites, was also present among local ruling groups and the sacrificial class.

Additionally, unlike the “female exogamy” pattern commonly reported in studies of ancient European societies, many adult women were found to have been buried within the same kinship networks. This suggests that Silla society during the Three Kingdoms period may have had a unique kinship structure with low gender bias.

Eunjin Woo, professor at Sejong University, told the Science and Technology Media Center Korea (SMCK), “It is academically significant to have genetically proven cousin marriage cases previously known only from historical records,” adding, “This research empirically demonstrates the group structures and customs of ancient people from information preserved in their bones.”

A partial family tree confirmed from the Imdang-Joyeong Tumulus Cluster of the Three Kingdoms period. The diagram illustrates kinship between tomb owners and cases of family-based funeral sacrifices, including female individuals born from cousin marriages. Gray figures represent individuals not excavated but inferred based on genetic relationships. Provided by the research team

Same Region, But No Mixing... Separation of Sacrificial Class

Particularly noteworthy is the relationship between principal tomb owners and sacrificial individuals. While both groups shared almost identical overall genetic backgrounds, they were clearly separated in terms of close kinship ties. This suggests that, rather than bringing in outsiders as sacrificial victims, certain strata within the same local society were strictly segregated and chosen for sacrifice.

There were also cases where sacrificial individuals with a parent-child relationship were found in the same tomb, raising the possibility that certain lineages were subjected to sacrifice over generations. This indicates that sacrificial burial was not a one-off ritual, but rather a structural practice tied to hereditary social order.

Professor Choongwon Jung of Seoul National University explained, “While the principal tomb owners and sacrificial groups were clearly separated in terms of kinship networks, their genetic profiles were identical. This is the first large-scale study to simultaneously reveal both the overall genetic homogeneity and the social stratification structure of Koreans during the Three Kingdoms period.”

This study marks the first large-scale ancient genome research focused on ancient Korean society. If expanded to the royal capital of Gyeongju and to tomb clusters in Baekje and Goguryeo regions in the future, it is expected to serve as a starting point for verifying the genetic realities of the bone rank system and marriage practices among the Three Kingdoms.

This content was produced with the assistance of AI translation services.