The Migration Period (300–500 CE) marked the end of Roman control in Austria and the beginning of significant upheaval as various tribes moved across Europe. Roman provinces like Noricum, Raetia, and Pannonia were increasingly unable to defend themselves against these invasions.
In 405 CE, the region was overrun by the army of the Gothic leader Radagaisus, and by 408 CE, the Visigoths under Alaric I passed through Noricum, staging operations from Virunum before later sacking Rome in 410. Though the Visigoths moved on, the area faced ongoing instability, including a brief incursion by the Huns in 451 CE. The death of Attila in 453 CE triggered the fragmentation of his empire, allowing new groups like the Rugii to establish independent territories along the Danube (Rugiland).
Routes of Barbarian invasions, 100–500. © MapMaster
From 472 CE, invasions by the Ostrogoths and Alamanni further eroded Roman authority, although remnants of the Roman administration persisted. Notably, figures like Severinus of Noricum attempted to maintain some order. However, by 476 CE, with the fall of the last Western Roman emperor, Roman influence collapsed. The final abandonment of Noricum came in 488 CE, while Raetia fell to the Alamanni.
By 493 CE, the region became part of the Ostrogothic Kingdom under Theodoric the Great, marking the transition from Roman to barbarian rule. After Theodoric’s death in 526 CE, the Ostrogothic realm began to unravel, completing the transformation of Austria from a Roman frontier to part of the early medieval world.