After his mission in Corduene Amminianus accompanied his commander when the latter rode out from his headquarters at Amida on a mission to make sure the bridges across the Euphrates were demolished. They were attacked by the Persian vanguard who had made a night march in an attempt to catch the Romans at Amida off guard. After a protracted cavalry battle the Romans were scattered, Ursicinus evaded capture and fled to Melitene while Ammianus barely made it back to Amida with a wounded comrade. The Persians started to besiege the city. When it fell Ammianus barely escaped with his life.