On this day in the year 313 AD, the Emperor Constantine, together with his co-emperor Licinius, issued the Edict of Milan, granting religious tolerance to Christians within the Roman Empire. The Church had been subjected to persecutions sporadically and locally almost from its beginning, and then suffered two general persecutions in the middle of the 3rd century, first under the emperor Decius in 250, and then under Valerian in 257. Although these both gave her a good number of martyrs, they failed on a fundamental level from the Roman point of view, in that they did nothing to arrest the growth of Christianity.
After the death of Valerian, in the midst of the political chaos of the 3rd century, there was a long period of relative peace until late in the reign of Diocletian, under whom the last and worst persecution began in 303. In the East, particularly Egypt, this was often very severe, but in much of the West, it was less rigorously enforced, and hardly enforced at all in Spain, Gaul and Britain, which were ruled by Constantine’s father. In 311, Galerius, the emperor in the East, recognizing that it had failed, issued an edict of toleration shortly before dying of a very nasty disease, which the writer Lactantius, the Christian Cicero, as he is called, describes as a “horrendous putrefaction that ran through all the members of his body.” However, his successor Maximin resumed persecution almost immediately, until his overthrow at the hands of Licinius in April of 313.
In June of that year, therefore, Constantine, now master of the West, and Licinius met in Milan to discuss the future of the Empire, and agreed to formally end the persecution, whence the above-named edict. This event very often has been misrepresented in two opposite ways. One is to say that Constantine made Christianity the official religion of the empire; I once attended a lecture delivered by someone who had every reason to know better, who not only repeated this historical error, but also claimed that Constantine expelled all the non-Christians from the whole empire.
The opposite error is to claim that the edict of Milan was issued for purely political reasons, since Constantine granted freedom not just to the Christians, but “to all others as well.” This fails to recognize that the edict as reported by Lactantius (On the deaths of the persecutors 48) repeatedly singles out the Christians by name, while mentioning no other religion specifically. “…it seemed to us … proper that the Christians and all others should have liberty to follow that mode of religion which to each of them appeared best… no man should be denied leave of attaching himself to the rites of the Christians, or to whatever other religion his mind directed him… the open and free exercise of their respective religions is granted to all others, as well as to the Christians,” and so on. Moreover, the edict orders that properties confiscated from the Christians be restored to them at the Empire’s expense, something which Galerius’ earlier edict of toleration had not done. Nor was there any other religion to which Constantine would prove such a stupendous benefactor for the rest of his reign, which would continue for almost a quarter of a century.