Genetic genealogy of the Piast dynasty and related European royal families.

The Piasts were one of the royal dynasties that shaped the political structure of medieval Europe in the 10th century CE. Despite their importance, as the founders and rulers of the early Polish kingdom, little is known about Piast origin, the conditions of Poland's transformation into a medieval monarchy, and generally about the mechanisms of political entity formation in 10th-century East-Central Europe. Here we present an interdisciplinary investigation of Piast necropolises scattered throughout Poland. Within eight sites, we find 33 sets of skeletal remains likely to belong to the Piasts. Archaeogenomic analyses confirm the identities of ten as Piasts. Based on genomic data obtained for them, we determine the mitochondrial haplogroups of more than 200 historical figures from 10 European royal dynasties. The Y haplogroup lineage identified in the Piasts (R1b-BY3549) is currently rare. The same Y haplogroup lineage in databases of ancient DNA is found in three individuals who lived in North-Western Europe (present-day France, the Netherlands, and England). Together, these findings may suggest that the Piasts were of non-local origin and support the hypothesis that the state-building processes occurring in the 9th-11th centuries in East-Central Europe were induced not only by local elites but also by foreigners.