Valentinian I (321-75), Western Roman emperor (364-75), born in Cibalae (near
modern Osijek, Croatia). He was an important military figure under the
emperors Julian and Jovian; upon the death of the latter, he was elected by
the Roman army to succeed Jovian. Valentinian chose his brother Valens to
share his rule, as Roman emperor of the East, and reserved for himself
Illyricum, Italy, Gaul (roughly conforming to modern France), Britain, Spain,
and north Africa. Under his administration, the Roman authority was restored
in Gaul, Africa, and Britain, and victories were won over the Alamanni.
Valentinian furthered education throughout his empire and provided medical
care for the poor of Rome; although an orthodox Christian, he was tolerant in
matters of religion.