Battle of the Frigidus

The Battle of the Frigidus was fought on 5–6 September 394 near the Frigidus River, usually identified with the Vipava in modern Slovenia. Theodosius I led an eastern army, including large numbers of Gothic federates, against the western regime of Eugenius and Arbogast.

Theodosius won after heavy fighting and became ruler of the whole Roman Empire. The victory was costly, and the role of Gothic troops and commanders such as Alaric and Stilicho mattered for later western politics. The empire was permanently divided between Theodosius’s sons after his death in 395.

Barbarian and the Throne builds towards the Frigidus through Videricus and Stilicho, placing barbarian service and Roman civil war in the same narrative. The battle gives fiction a setting of mountain terrain, divided legitimacy, federate troops and a victory that does not restore long-term stability.