Theodosius I, also known as Theodosius the Great, was a Roman Emperor from 379 to 395 AD. Born in Spain in 347 AD, his reign marked a pivotal moment in the history of the Roman Empire, particularly in terms of its religious transformation.
Theodosius was born into a military family, his father being the prominent general Count Theodosius. After his father's execution in 376 AD by order of Emperor Valens, Theodosius retired to his estates in Spain. However, following the disastrous defeat at the Battle of Adrianople in 378 AD, where Valens was killed, the eastern Roman Empire was in dire need of a capable leader. Theodosius was summoned back to service and was proclaimed co-emperor with Gratian in January 379 AD.
Upon his ascension, Theodosius focused on stabilizing the eastern frontiers against the Goths and other barbarian tribes. He achieved a peace treaty with the Goths in 382 AD, allowing them to settle within the empire's borders as federates, which significantly altered the demographic and military landscape of the region.
Theodosius is particularly noted for his role in Christianizing the Roman Empire:
Theodosius also undertook several administrative reforms:
Upon his death in 395 AD, Theodosius left the empire divided between his two sons, Arcadius in the East and Honorius in the West, effectively marking the permanent division of the Roman Empire. His reign set precedents for the Byzantine Empire, particularly in its religious orientation and administrative structure.