Constantine I (27 February 272 – 22 May 337), also known as Constantine the Great, was Roman emperor from AD 306 to 337 and the first Roman emperor to convert to Christianity.[h] He played a pivotal role in elevating the status of Christianity in Rome, the Edict of Milan decriminalizing Christian practice and ceasing Christian persecution. This was a turning point in the Christianization of the Roman Empire. He founded the city of Constantinople (now Istanbul) and made it the capital of the Empire, which it remained for over a millennium.