Constantine the Great (272-337) & the Christianization of the Roman Empire

Constantine Flavius Valerius Constantinus was the first Roman Emperor to convert to Christianity. He was a Roman emperor from AD 306-337 (alone from 19th September 324 after defeating Maxentius and Licinius and ending the civil war).

He played a pivotal role in elevating the status of Christianity in Rome by decriminalizing Christian practice and ceasing Christian persecution in a period referred as the Constantinian shift. This initiated the Christianization of the Roman Empire.

He spent much of his life as a pagan.
Sources differ on when he was baptised
2 sources suggest In 312 he became a Christian and was baptised by either Eusebius of Nicomedia or Pope Sylvester1.
Another source suggests he was baptised just before he died.

In 313 he played an influential role in the proclamation of the Edict of Milan
which declared tolerance for Christianity in the Roman Empire.
In 321 he legislated that the venerable Sunday should be a day of rest for all citizens
In 325 he convoked the First Council Nicaea - result the Nicene Creed.

The Church of the Holy Sepulchre was built in Jerusalem on his orders and declared to be the holiest place in all Christendom.

Before Constantine fought Maxentius in 324 he is said, by Lactantius, to have had a dream. He was told to put the Greek letters Chi Rho, Christ’s initials, on the shields. He won the battle.
( Read Constantine adopts the Greek Letters Chi Rho for Christ’s initials)

The Historiography I have included has different historians rating the greatness of Constantine. They come to different conclusions.

I am not an historian -read their thoughts and come to your own conclusion.

Nevertheless he is venerated as a saint in Eastern Christianity, and he did much to push Christianity toward the mainstream of Roman culture
Wikipedia
Sources
Wikipedia
70 Great Christians by Geoffrey Hanks