Bronze Coin of Emperor Constantine I the Great - C.4473Origin: Minted in Nicomedia Circa: 307 AD to 337 AD Collection: Numismatics Style: Roman Medium: Bronze Constantine I, called Constantine the Great, was the first Roman ruler to be converted to Christianity. He was the founder of Constantinople (present-day Istanbul), which remained the capital of the Eastern Roman (Byzantine) Empire until 1453. Constantine the Great unified a tottering empire, reorganized the Roman state, and set the stage for the final victory of Christianity at the end of the 4th century. Many modern scholars accept the sincerity of his religious conviction. His conversion was a gradual process; at first he probably associated Christ with the victorious sun god. By the time of the Council of Nicaea (325), however, he was completely Christian, but still tolerated paganism among his subjects. Although criticized by his enemies as a proponent of a crude and false religion, Constantine the Great strengthened the Roman Empire and ensured its survival in the East. As the first emperor to rule in the name of Jesus Christ, he was a major figure in the foundation of medieval Christian Europe.