Theodosios I the Great
Theodosios I the Great (b. Cauca, Galicia, 347-d. Mediolanum, 395), son of a Roman army general of the same name, was the last emperor (379-395) of the undivided Roman empire. Following the death of the emperor Valens in a battle against the Goths, Theodosios was proclaimed "augustus" and assumed the government of the East and of eastern Illyricum.

It was only in 394 that he became the sole sovereign of the Eastern and Western halves of the Empire after defeating in battle usurpers of the throne of Rome. In order to deal more effectively with the attack mounted by the Goths upon the Balkans, Theodosios established himself in Thessalonike in about 379.

The treaty of 382 allowed the Goths to settle as fief-holders in the deserted regions between the Danube and the mountainous northern frontier of the Haimos Peninsula. While in Mediolanum (present-day Milano) in 390, Theodosios violently suppressed a rising in Thessalonike against the authorities by ordering the massacre of thousands of citizens.

By his edict of 380 he recognized Christianity as the official religion of the state, seeking through its encouragement to secure the unity of the Empire. Among the measures he adopted against other religions was the abolition of the Olympic Games and the enactment of penal and administrative sanctions against heretics.

The second Ecumenical Council, convened by him, finalized the Articles of Faith, but an attempt to regulate the internal organization of the Church sowed the seeds of the ecclesiastical factions that emerged in the 5th century. Notwithstanding his pro-Christian stance (he was baptized in 380 in Thessalonike), Theodosios did employ heathens (e.g. the rhetorician Themistios) in the highest offices of state.

Though lacking a reformative character, his legislation betrays a positive approach to the social problems of the time. Finally, according to several historians, the administrative division of the Empire's Eastern and Western parts between Theodosios' sons Honorios and Arcadios after their father's death in 395 marks the birth of the Byzantine state.