wikipediaTheodosius I (Latin: Flavius Theodosius Augustus;[1] Greek: Θεοδόσιος Αʹ; 11 January 347 – 17 January 395), also known as Theodosius the Great, was a Roman Emperor from 379 to 395, and the last emperor to rule over both the Eastern and the Western halves of the Roman Empire. On accepting his elevation, he campaigned against Goths and other barbarians who had invaded the Empire. His resources were not sufficient to destroy them or drive them out, which had been Roman policy for centuries in dealing with invaders. By treaty, which followed his indecisive victory at the end of the Gothic War, they were established as foederati, autonomous allies of the Empire, south of the Danube, in Illyricum, within the Empire's borders. They were given lands and allowed to remain under their own leaders, a grave departure from Roman hegemonic ways. This turn away from traditional policies was accommodationist and had grave consequences for the Western Empire from the beginning of the century, as the Romans found themselves with the impossible task of defending the borders and dealing with unruly federates within. Theodosius I was obliged to fight two destructive civil wars, successively defeating the usurpers Magnus Maximus in 387–388 and Eugenius in 394, though not without material cost to the power of the Empire.
He issued decrees that effectively made Nicene Christianity the official state church of the Roman Empire.[2][3] He neither prevented nor punished the destruction of prominent Hellenistic temples of classical antiquity, including the Temple of Apollo in Delphi and the Serapeum in Alexandria. He dissolved the Order of the Vestal Virgins in Rome. In 393, he banned the pagan rituals of the Olympics in Ancient Greece. After his death, Theodosius's young sons Arcadius and Honorius inherited the east and west halves of the empire respectively, and the Roman Empire was never again re-united, though Eastern Roman emperors after Zeno would claim the united title after Julius Nepos's death in 480.
Theodosius is considered a saint by the Armenian Apostolic Church and Eastern Orthodox Church[4], and his feast day is on January 17.[5].