Croatia — Early Medieval Echoes

Between the 7th and 13th centuries CE, the region that is now Croatia became a crossroads of mobility, cultural reorganization and evolving identities. Archaeological data from three sampled localities—Glina (Sisak‑Moslavina County, Grad Glina), Gornji‑Kosinj‑Sveta‑Ana (Lika‑Senj County, Općina Perušić) and Cepinski‑Martinci (Osijek‑Baranja County, Općina Čepin)—capture snapshots of communities living in a landscape shaped by migrations, trade routes and shifting political horizons.

Material traces in the Early Medieval period include settlement traces, burial assemblages and artifacts that signal interaction between local traditions and wider Adriatic‑Danubian networks. Limited evidence suggests these populations integrated elements from incoming Slavic groups, Byzantine contacts, and longstanding local practices. Radiocarbon and typological dating place the sampled individuals between ca. 650 CE and 1250 CE, a span that encompasses early post-Roman transformations and the consolidation of regional polities.

Genetically, the samples hint at layered ancestry rather than a single origin: composite signals consistent with longstanding European lineages together with inputs that are more common to southern or eastern Mediterranean populations. Because the dataset includes only nine individuals, these impressions remain provisional and should be read as initial glimpses into a complex formative era.

Nine individuals provide the genetic core of this dataset—small but illuminating. Y‑chromosome haplogroups are dominated by R lineages (4 individuals) with at least one J lineage (1 individual). Mitochondrial lineages are primarily U (5), with T (2), I (1) and W3b (1) represented. These markers together paint a picture of predominantly European maternal ancestry (U, I, W) alongside maternal lineages (T) that have broader Eurasian distributions.

Haplogroup R is widespread across Europe and can reflect continuity with long‑standing continental male lineages; without subclade resolution it is not possible to distinguish R1a versus R1b dynamics here. Haplogroup J, comparatively rarer in this small set, is often associated in broader studies with Mediterranean and Near Eastern connections—its presence may indicate gene flow along trade or migration routes. The high proportion of U mitogenomes echoes signals found across Europe from prehistoric hunter‑gatherers through later populations, suggesting substantial local maternal continuity.

Because the sample count is fewer than ten, genetic inferences are preliminary. Archaeogenetic interpretation benefits from integrating these results with additional genomes, isotopic data and archaeological context. Still, the combination of European‑common maternal lineages and mixed paternal signals aligns with a scenario of local continuity overlaid with episodic incoming ancestry during the Early Medieval centuries.