Theodosius I, the Great c.347-395AD
Roman emperor

The son of Theodosius the Elder (d.367AD), he was born in Cauca in north-west Spain. He was appointed by Gratian as his co-emperor in the East (379). He campaigned against the Goths, but allowed them to settle within the Roman Empire (382). He secured peace with the Persian Sassanids by partitioning Armenia (c.386). When the usurper Magnus Maximus expelled Valentinian II from Italy (387), Theodosius marched west and defeated and killed him at Aquileia (388). He was a devout Christian, and St Ambrose had great influence over him. When Theodosius massacred the rebellious citizens of Thessalonika, Ambrose excommunicated him for eight months until he had done public penance. In 392 Valentinian II was murdered, and in 394 Theodosius marched against the Franks and their puppet emperor Eugenius. He defeated Eugenius, and for the remaining four months of his life ruled as sole Roman emperor. In 381 he affirmed the Nicene Creed, pursued heretics and pagans, and in 391 ordered the closing of all temples and banned all forms of pagan cult.

Bibliography: Noel Q King, The Emperor Theodosius and the Establishment of Christianity (1960)