Ancient genomes reveal Avar-Hungarian transformations in the 9th-10th centuries CE Carpathian Basin.

During the Early Medieval period, the Carpathian Basin witnessed substantial demographic shifts, notably under the Avar dominance for ~250 years, followed by the settlement of early Hungarians in the region during the late 9th century CE. This study presents the genetic analysis of 296 ancient samples, including 103 shotgun-sequenced genomes, from present-day Western Hungary. By using identity-by-descent segment sharing networks, this research offers detailed insights into the population structure and dynamics of the region from the 5th to 11th centuries CE, with specific focus on certain microregions. Our evaluations reveal spatially different histories in Transdanubia even between communities in close geographical proximity, highlighting the importance of dense sampling and analyses. Our findings highlight extensive homogenization and reorganization processes, as well as discontinuities between Hun, Avar, and Hungarian conquest period immigrant groups, alongside the spread and integration of ancestry related to the Hungarian conquerors.