After a long-distance migration, Avars with Eastern Asian ancestry arrived in Eastern Central Europe in 567 to 568 ce and encountered groups with very different European ancestry^1,2. We used ancient genome-wide data of 722 individuals and fine-grained interdisciplinary analysis of large seventh- to eighth-century ce neighbouring cemeteries south of Vienna (Austria) to address the centuries-long impact of this encounter^1,2. We found that even 200 years after immigration, the ancestry at one site (Leobersdorf) remained dominantly East Asian-like, whereas the other site (Mödling) shows local, European-like ancestry. These two nearby sites show little biological relatedness, despite sharing a distinctive late-Avar culture^3,4. We reconstructed six-generation pedigrees at both sites including up to 450 closely related individuals, allowing per-generation demographic profiling of the communities. Despite different ancestry, these pedigrees together with large networks of distant relatedness show absence of consanguinity, patrilineal pattern with female exogamy, multiple reproductive partnerships (for example, levirate) and direct correlation of biological connectivity with archaeological markers of social status. The generation-long genetic barrier was maintained by systematically choosing partners with similar ancestry from other sites in the Avar realm. Leobersdorf had more biological connections with the Avar heartlands than with Mödling, which is instead linked to another site from the Vienna Basin with European-like ancestry. Mobility between sites was mostly due to female exogamy pointing to different marriage networks as the main driver of the maintenance of the genetic barrier.

The second half of the first millennium ce in Central and Eastern Europe was accompanied by fundamental cultural and political transformations. This period of change is commonly associated with the appearance of the Slavs, which is supported by textual evidence^1,2 and coincides with the emergence of similar archaeological horizons^3–6. However, so far there has been no consensus on whether this archaeological horizon spread by migration, Slavicisation or a combination of both. Genetic data remain sparse, especially owing to the widespread practice of cremation in the early phase of the Slavic settlement. Here we present genome-wide data from 555 ancient individuals, including 359 samples from Slavic contexts from as early as the seventh century ce. Our data demonstrate large-scale population movement from Eastern Europe during the sixth to eighth centuries, replacing more than 80% of the local gene pool in Eastern Germany, Poland and Croatia. Yet, we also show substantial regional heterogeneity as well as a lack of sex-biased admixture, indicating varying degrees of cultural assimilation of the autochthonous populations. Comparing archaeological and genetic evidence, we find that the change in ancestry in Eastern Germany coincided with a change in social organization, characterized by an intensification of inter- and intra-site genetic relatedness and patrilocality. On the European scale, it appears plausible that the changes in material culture and language between the sixth and eighth centuries were connected to these large-scale population movements.

Uniparental genetic systems are unique sex indicators and complement the study of autosomal diversity by providing landmarks of human migrations that repeatedly shaped the structure of extant populations. Our knowledge of the variation of the male-specific region of the Y chromosome in Native Americans is still rather scarce and scattered, but by merging sequence information from modern and ancient individuals, we here provide a comprehensive and updated phylogeny of the distinctive Native American branches of haplogroups C and Q. Our analyses confirm C-MPB373, C-P39, Q-Z780, Q-M848, and Q-Y4276 as the main founding haplogroups and identify traces of unsuccessful (pre-Q-F1096) or extinct (C-L1373*, Q-YP4010*) Y-chromosome lineages, indicating that haplogroup diversity of the founder populations that first entered the Americas was greater than that observed in the Indigenous component of modern populations. In addition, through a diachronic and phylogeographic dissection of newly identified Q-M848 branches, we provide the first Y-chromosome insights into the early peopling of the South American hinterland (Q-BY104773 and Q-BY15730) and on overlying inland migrations (Q-BY139813).

The Late Bronze Age (ca. 1300–800 BCE) of Central Europe is often characterised as a period of increasing mobility, socioeconomic transformation, environmental fluctuations, and expanding cultural networks. However, reconstructing the demographic aspects of these changes has been hindered by cremation being the dominant mortuary practice, limiting biomolecular approaches. Here, we integrate ancient DNA, oxygen and strontium isotope analyses, and osteoarchaeology to examine rare inhumation burials from Kuckenburg and Esperstedt in Central Germany (n = 36) and compare them to contemporaneous inhumations from the neighbouring regions of South Germany, Bohemia (Czechia) and Southwest/Central Poland (n = 33). Genome-wide data show genetic continuity with preceding Early Bronze Age populations, alongside gradual increases in Early European Farmer-related ancestry, albeit with regionally different timing and extent, reflecting a nuanced pattern of mobility and admixture. Oxygen and strontium isotope data from Central Germany indicate that most individuals match the local isotope signal, including those who were cremated or had a different diet, and with only a few isotopic outliers, suggesting that mobility was present but not extensive. Overall, our findings suggest that the diverse inhumation practices at Kuckenburg and Esperstedt were culturally motivated, reflecting local traditions and ongoing regional interconnectedness rather than the influx of new genetic groups or non-local individuals.

Archaeological and archaeogenetic studies have highlighted the pivotal role of the Caucasus region throughout prehistory, serving as a central hub for cultural, technological, and linguistic innovations. However, despite its dynamic history, the critical area between the Greater and Lesser Caucasus mountain ranges, mainly corresponding to modern-day Georgia, has received limited attention. Here, we generated an ancient DNA time transect consisting of 219 individuals with genome-wide data from 47 sites in this region, supplemented by 97 new radiocarbon dates. Spanning from the Early Bronze Age 5000 years ago to the so-called ‘Migration Period’ that followed the fall of the Western Roman Empire, we document a largely persisting local gene pool that continuously assimilated migrants from Anatolia/Levant and the populations of the adjacent Eurasian steppe. More specifically, we observe these admixture events as early as the Middle Bronze Age. Starting with Late Antiquity (late first century AD), we also detect an increasing number of individuals with more southern ancestry, more frequently associated with urban centers – landmarks of the early Christianization in eastern Georgia. Finally, in the Early Medieval Period starting 400 AD, we observe genetic outlier individuals with ancestry from the Central Eurasian steppe, with artificial cranial deformations (ACD) in several cases. At the same time, we reveal that many individuals with ACD descended from native South Caucasus groups, indicating that the local population likely adopted this cultural practice.

The transformation of the Roman world [fourth to ninth centuries common era (CE)], culminating in the Western Roman Empire’s fall, marked a fundamental transition in European history. Key questions persist regarding the regionally specific nature of this transformation. We generated a paleogenomic dataset to reconstruct post-Roman organizations in the Little Hungarian Plain at microregional resolution. Genetic and archaeological analyses of two Roman ( n = 68) and five post-Roman ( n = 246) sites reveal a rise in Northern European ancestry, reflecting large-scale population movements into this region. Moreover, despite post-Roman sites sharing similar genetic profiles, material culture, and burial practices, they show distinct social structures, especially regarding the role played by biological relatedness. These findings highlight local hierarchies and reveal the making of a post-Roman polity.