The Edict of Milan was an important step in securing the civil rights of Christians throughout the Roman Empire. For nearly three hundred years, Christianity was functionally illegal in the Roman Empire. Christians were subject to various levels of persecution, up to and including arrest or execution, depending on the whims of the ruling politicians. In AD 311, the Roman Emperor Galerius issued a decree that Christians be treated with “toleration.” In practice, this simply cancelled the official persecution of Christianity begun by Diocletian in 303. Return of confiscated property and the restoration of rights were not, however, part of Galerius’s decree.
In 313, the Western emperor, Constantine, met with his rival and counterpart, the Eastern emperor, Licinius, in the city of Milan, Italy. As part of their discussions, they issued a joint statement, later known as the Edict of Milan. This proclamation protected full rights for Christian citizens of the Empire, restoring their property, releasing them from prisons, and effectively banning government persecution of their faith. It also declared a general state of religious tolerance, allowing for the expression of virtually any spiritual belief.
Although the Edict of Milan was a landmark in Christian history, it was essentially a footnote to the history of the man primarily responsible for it: Constantine. Though the edict declared tolerance for all faiths, Constantine’s public endorsement of Christianity expanded over his reign. Christianity, a growing subculture within the Roman Empire when the Edict of Milan was issued, became the de facto religion of the Roman Empire by the time of Constantine’s death. Persecutions had been cancelled in the past, but the Edict of Milan in 313 went further by directly protecting the religious rights of Romans. That and the support of a strongly pro-Christian leader made an official end to the Roman oppression of Christians.