Emperor Theodosius I is baptized and declares Christianity to be the official religion of the Empire.
Roman Emperors Theodosius I and Gratianus declare that the patriarchs of Rome and Alexandria hold primacy (above especially the one of Constantinople), implicitly rejecting Arianism in favor of orthodox Christianity.
Bedouin Queen Mavia's Saracen troops defeat a Roman army.
Invasion of the Vandals. Gratian is forced to cede Upper Pannonia to them.