Flavius Valerius Aurelius Constantinus (27 February ca. 272 – 22 May 337), commonly known as Constantine I, Constantine the Great (among Roman Catholics), or Saint Constantine (among Eastern Orthoox and Byzantine Catholic Christians), was Roman Emperor from 306, and the undisputed holder of that office from 324 to his death. Best known for being the first Christian Roman Emperor, Constantine reversed the persecutions of his predecessor, Diocletian, and issued (with his co-emperor Licinius) the Edict of Milan in 313, which proclaimed religious toleration throughout the empire.