The period from roughly 200 to 800 CE in what is now Croatia is a time of layered transformation: the gradual unraveling of Roman imperial structures, the persistence of Mediterranean lifeways on the coast, and movements of peoples across the Balkans. Archaeological data from coastal towns such as Sipar (Grad Umag, Istria) and Hvar (Hvar-Radošević, Split-Dalmatia) show continuity in trade goods, ceramics, and maritime infrastructure that often echo earlier Roman patterns. Inland sites — Gardun (Grad Trilj) and Sisak-Pogorelec (Grad Sisak) — reveal fortified settlements and reconfigured rural landscapes responding to shifting political realities.
Limited evidence suggests that some communities maintained long-term continuity of local elites and craft traditions, while others incorporated newcomers whose material culture and burial practices differ subtly from earlier Roman norms. The archaeological picture is not uniform: coastal cemeteries and harbor contexts emphasize commerce and Mediterranean connections, whereas inland fortifications reflect strategic, sometimes martial, adaptations.
Genetically, the region appears to record a tapestry of ancestries: Mediterranean and Near Eastern affinities alongside Balkan and steppe-derived components. These genetic signals are consistent with a zone of mobility — soldiers, merchants, and migrating groups — overlaying deep local roots. Archaeological context is critical: material continuity does not preclude demographic change, and limited sampling in specific cemeteries requires cautious interpretation.