The process by which Christianity came to occupy the commanding heights of the Roman mind was long, complex, and gradual. A crucial phase in this evolution was marked by two laws responsible for bringing to a final end the Great Persecution (303–313 CE) of the Christian Church in the Roman Empire. Persecution had already ceased in the western half of the empire in 306 CE. The Edict of Galerius, issued in the spring of 311, was intended to end persecution in the eastern half. However, persecution in the East started up again before the end of 311 under Galerius’s successor. It was not until the summer of 313 that Licinius, the emperor controlling the eastern half of Roman Empire, together with Constantine, the emperor of the western half of the Roman Empire and the first Christian Roman emperor, issued the Letter of Licinius ( formerly known as the Edict of Milan). It was after Constantine eliminated Licinius in 324 that pagan sacrifice was made illegal, important temples were destroyed and their treasures confiscated, and the conditions existed for the eventual creation of a distinctively Christian Roman civilization.