Theodosius I
Emperor
Sanctified Life
347 — 395
Also Known As
Patronage
"We authorize the followers of this law to assume the title of Catholic Christians."
The last Emperor to rule both the Eastern and Western halves of the Roman Empire, Theodosius turned the tide of history by establishing Nicene Christianity as the official faith of the state. Though a powerful ruler who navigated civil wars and the Gothic threat, his most enduring legacy is his submission to Church authority—famously accepting penance from St. Ambrose after the Massacre of Thessalonica, proving that even Caesars are subject to the Kingdom of God.

Historical Journey
Life Locations
Historical Depiction

Wikimedia Commons Source
Titles & Roles
Works & Prayers
Edict of Thessalonica
The decree declaring Nicene Christianity the official religion of the Roman Empire.
Read MoreYour life was a pillar of the faith, O Theodosius; By your words and deeds you strengthened the Church, And brought the Empire to the worship of the Truth. O righteous Emperor, pray to Christ our God to grant us His great mercy.
Gallery

Roman empire 395
Shepherd, William R. • 1923
The administrative divisions of the Roman Empire in 395, under Theodosius I.
Sacred Symbols
orb and_cross
Christian Dominion
scroll
Edict of Thessalonica
Life Journey
Early Life
Born 347 in Hispania. Rose through military ranks but was forced into retirement after his father's execution.
Turning Point
379. Recalled by Emperor Gratian after the Battle of Adrianople to save the East from the Goths. He was appointed Co-Emperor.
Legacy
Issued the Edict of Thessalonica (380) making Christianity the state religion. Defeated usurpers in the West to briefly reunite the Empire before his death in 395.
Related Saints
Connections in the communion of saints
Constantine the Great
Theodosius made Christianity the sole religion of Rome, completing Constantine's vision.
Ambrose
Ambrose famously required Theodosius to do public penance for the Thessalonica massacre.
Justinian I
Justinian looked to Theodosius's codification of Christian law as a model for his own reforms.
Ambrose
Ambrose famously excommunicated Emperor Theodosius after the Thessalonica massacre, demanding public penance.