It is possible that he was dismissed from his command by the emperor Valentinian I after the loss of two of Theodosius' legions to the Sarmatians in late 374. From 364 to 375, the Roman Empire was governed by two co-emperors, the brothers Valentinian I and Valens; when Valentinian died in 375, his sons, Valentinian II and Gratian, succeeded him as rulers of the Western Roman Empire.