Ever since the fall of the Severan dynasty in 235 AD, rivals for the imperial throne had bid for support by either favouring or persecuting Christians. The previous Edict of Toleration by Galerius had been recently issued by the emperor Galerius from Serdica and was posted at Nicomedia on 30 April 311. By its provisions, the Christians, who had “followed such a caprice and had fallen into such a folly that they would not obey the institutes of antiquity”, were granted an indulgence.
Wherefore, for this our indulgence, they ought to pray to their God for our safety, for that of the republic, and for their own, that the commonwealth may continue uninjured on every side, and that they may be able to live securely in their homes.
Their confiscated property, however, was not restored until 313, when instructions were given for the Christians’ meeting places and other properties to be returned and compensation paid by the state to the current owners:
the same shall be restored to the Christians without payment or any claim of recompense and without any kind of fraud or deception.
It directed the provincial magistrates to execute this order at once with all energy so that public order may be restored and the continuance of divine favour may “preserve and prosper our successes together with the good of the state.”
The actual letters have never been retrieved. However, they are quoted at length in Lactantius‘ On the Deaths of the Persecutors (De mortibus persecutorum), which gives the Latin text of both Galerius’s Edict of Toleration as posted at Nicomedia on 30 April 311 and of Licinius‘s letter of toleration and restitution addressed to the governor of Bithynia and posted at Nicomedia on 13 June 313.
Eusebius of Caesarea translated both documents into Greek in his History of the Church (Historia Ecclesiastica). His version of the letter of Licinius must derive from a copy posted in the province of Palaestina Prima (probably at its capital, Caesarea) in the late summer or early autumn of 313, but the origin of his copy of Galerius’s Edict of 311 is unknown since that does not seem to have been promulgated in Caesarea. In his description of the events in Milan in his Life of Constantine, Eusebius eliminated the role of Licinius, whom he portrayed as the evil foil to his hero Constantine.
The Edict was in effect directed against Maximinus Daia, the Caesar in the East who was at that time styling himself as Augustus. Having received the emperor Galerius’ instruction to repeal the persecution in 311, Maximinus had instructed his subordinates to desist, but had not released Christians from prisons or virtual death-sentences in the mines, as Constantine and Licinius had both done in the West.
Following Galerius’ death, Maximin was no longer constrained; he enthusiastically took up renewed persecutions in the eastern territories under his control, encouraging petitions against Christians. One of those petitions, addressed not only to Maximin but also to Constantine and Licinius, is preserved in a stone inscription at Arycanda in Lycia, and is a “request that the Christians, who have long been disloyal and still persist in the same mischievous intent, should at last be put down and not be suffered by any absurd novelty to offend against the honour due to the gods.”
The Edict is popularly thought to concern only Christianity, and even to make Christianity the official religion of the Empire (which recognition did not actually occur until the Edict of Thessalonica in 380). Indeed, the Edict expressly grants religious liberty not only to Christians, who had been the object of special persecution, but goes even further and grants liberty to all religions:
When you see that this has been granted to [Christians] by us, your Worship will know that we have also conceded to other religions the right of open and free observance of their worship for the sake of the peace of our times, that each one may have the free opportunity to worship as he pleases; this regulation is made that we may not seem to detract from any dignity of any religion.
— “Edict of Milan”, Lactantius, On the Deaths of the Persecutors (De Mortibus Persecutorum), ch. 48. opera, ed. 0. F. Fritzsche, II, p 288 sq. (Bibl Patr. Ecc. Lat.XI).
Since Licinius composed the Edict with the intent of publishing it in the east upon his hoped-for victory over Maximinus, it expresses the religious policy accepted by Licinius, a pagan, rather than that of Constantine, who was already a Christian. Constantine’s own policy went beyond merely tolerating Christianity: he tolerated paganism and other religions, but he actively promoted Christianity.
Although the Edict of Milan is commonly presented as Constantine’s first great act as a Christian emperor, it is unlikely that the Edict of Milan was an act of genuine faith. The document should instead be seen as Constantine’s first step in creating an alliance with the Christian God, who he considered the strongest deity. At that time, he was more concerned about social stability and the protection of the empire from the wrath of the Christian God than he was for justice or care for the Christians. The edict is more indicative of Roman culture’s obsession with seeking the gods’ intervention than of Constantine’s or Licinius’s religious beliefs.