Cosmopolitanism in the depths of Barbaricum evidenced by archaeogenomic data from the Late Iron Age Goth community of the Masłomęcz group

Background: High mobility and extensive trade and military interactions are well recognized throughout the Late Iron Age Europe. The extremely rich archaeological record for the Masłomęcz group – a Goth-associated assemblage flourishing between 2nd and 4th century CE in what is now eastern Poland – has long been providing evidence for their wide cross-cultural contacts. However, the extent to which these were ephemeral or involved long-term immigration and interbreeding, remained unresolved. Results: Here, by obtaining archaeogenomic data from 37 burials and reanalysing published data, we provide evidence that, while the Masłomęcz group was built mostly on Scandinavian-derived ancestry it extensively assimilated individuals from diverse directions and distances, including the Baltics, the Balkans and even further into the Mediterranean, creating a highly genetically heterogenous population. Additionally, we shed more light on the burial customs of this community by finding no close kin relations within multiperson burials. Conclusions: Our findings provide evidence for long-range mobility far outside the borders of the Roman Empire. The Masłomęcz group was a highly open community embracing external contacts and immigration, perhaps contradicting popular presumptions about the so-called barbarians.