Constantine the Great also known as Constantine I or Saint Constantine, was Roman Emperor from 306 to 337. Well known for being the first Roman emperor to convert to Christianity, Constantine and co-Emperor Licinius issued the Edict of Milan in 313, which proclaimed religious tolerance of all religions throughout the empire.
The foremost general of his time, Constantine defeated the emperors Maxentius and Licinius during civil wars. He also fought 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 built a new imperial residence in place of Byzantium, naming it Constantinople, which would later be the capital of the Eastern Roman Empire for over one thousand years. He is thought of as the founder of the Eastern Roman Empire.