Constantine I[g] (Flavius Valerius Constantinus; 27 February c. 272 – 22 May 337), also known as Constantine the Great, was a 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, 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 and made it the capital of the Empire, which it remained for over a millennium.