Theodosius I

Born in Hispania in 347, son of a general executed under murky circumstances, Theodosius clawed back from forced retirement through court intrigue and was named eastern emperor in 379 after Valens fell at Adrianople. His depleted forces couldn't expel the Goths, so in 382 he let them settle south of the Danube as autonomous allies - a peace that held in his lifetime but seeded future trouble. He convened the First Council of Constantinople in 381, cementing the Nicene Creed as orthodoxy and Arianism as heresy, and married into the western dynasty to shore up his position. Twice he marched west to crush usurpers, the second time in 394 against Eugenius, a victory that made him sole ruler of both halves. He died in January 395, five months later, leaving the empire to his young sons Arcadius and Honorius, who ruled separately and poorly from then on.