Constantine the GreatCon‧stan‧tine the Great /ˌkɒnstəntaɪn ðə ˈɡreɪt $ ˌkɑːn-/ (also Constantine I /-ðə ˈfɜːst $ -ˈfɜːrst/)(?274–337 AD) the first Christian ruler of the roman empire. In 330 AD he made byzantium the capital city of the empire instead of Rome and changed the name of the new capital to Constantinople. →Byzantine