Constantine the Great (Latin: Flavius Valerius Aurelius Constantinus Augustus; c. 27 February 272– 22 May 337), also known as Constantine I or Saint Constantine, is Roman Emperor from 306 to 337.

Well known for being the first Roman emperor to convert to Christianity, Constantine and co-Emperor Licinius issue the Edict of Milan in 313, which proclaims religious tolerance of all religions throughout the empire.

The foremost general of his time, Constantine defeats the emperors Maxentius and Licinius during civil wars.

He also fights successfully against the Franks, Alamanni, Visigoths, and Sarmatians during his reign—even resettling parts of Dacia which had been abandoned during the previous century.

Constantine builds a new imperial residence in place of Byzantium, naming it New Rome.

However, in Constantine's honor, people call it Constantinople, which will later be the capital of the Eastern Roman Empire for over one thousand years.

Because of this, he is thought of as the founder of the Eastern Roman Empire.