In February 313, Constantine and Licinius reached an agreement at Milan supporting broad religious toleration, including for Christians. The policy was then publicized in the East by Licinius later in 313, ordering the restoration of confiscated Christian property and legal rights. This moved Christianity from tolerated survival toward protected public existence.
Imperial directives in 313 instructed provincial officials to restore property taken from Christian communities during earlier persecutions. This mattered because it turned toleration into practical support: churches regained buildings, land, and resources needed for worship and organization. It also signaled that Christian institutions could now appeal directly to the emperor.
Constantine convened the Council of Arles to deal with the Donatist controversy in North Africa, where Christians disputed which bishops and sacraments were legitimate after persecution. The council condemned the Donatists, but the conflict continued. The episode showed a new pattern: the emperor acting as a sponsor and organizer for church unity.
Constantine issued a civil law ordering many city residents and officials to rest on the “venerable day of the sun,” while allowing farm work to continue. The law was not a direct order to worship, but it aligned imperial timekeeping with a weekly rhythm that many Christians already observed. It shows how imperial law could begin shaping public life in ways that favored Christian practice.
The Lateran Basilica (St. John Lateran) was consecrated in 324 and became the earliest public church in Rome with top rank in later Catholic tradition. Constantine’s support—linked to the transfer of the Lateran property to the bishop of Rome—helped give Roman Christianity a prominent civic location. This reflected a shift from house churches and tolerated gatherings to monumental, publicly visible worship spaces.
After becoming sole ruler, Constantine rebuilt Byzantium as a new imperial center and dedicated it as “New Rome,” later known as Constantinople. The new capital placed the emperor closer to the empire’s eastern provinces, where many major church debates and councils took place. Over time, Constantinople would become a leading center of Christian politics, worship, and administration.
Constantine and the Christianization of the Roman Empire (306–337)