Theodosius I the Great

Theodosius I (347–395), called the Great, was Roman emperor from 379 to 395 and the last man to rule the whole Roman Empire. Born at Cauca in Hispania, after Valens fell to the Goths at Adrianople, Gratian invested him with the purple at Sirmium in 379.

He could not drive the Goths out; in 382 he settled them south of the Danube as autonomous allies. The Council of Constantinople in 381 made Nicene Christianity orthodoxy against Arianism. He defeated Magnus Maximus in 388 and Eugenius at the Frigidus in September 394.

In 390, after a riot at Thessalonica killed his general Butheric, Roman troops slaughtered thousands of its people; Ambrose of Milan made him do penance without his robes until Christmas. He died at Milan on 17 January 395, leaving the east to Arcadius and the west to Honorius; the division lasted until the West fell.