A study by international researchers has found that a Korean society, about 1,500 years ago, used human sacrifice to honor local royalty in what is now South Korea. The study, which also revealed a dense kinship system focused on women and their descendants, investigated 78 skeletons from the Imdang-Joyeong burial complex in Gyeongsan, located in the southeast region of the Korean Peninsula. The tombs were constructed between the fourth and sixth centuries during the Three Kingdoms period, during which the society favored "consanguineous" marriage between related individuals. The researchers found 11 pairs of people who were first-degree relatives, 23 pairs of second-degree cousins, and five individuals whose parents were closely related. The findings could help explain how the practice of human sacrifice on entire families raises questions about institutionalized violence, slavery and social mobility in the 1,600-year-old Korean kingdom.