On this date, Gaius Flavius Valerius Aurelius Constantinus (27 February 272 C.E.–22 May 337 C.E.) commonly known as Constantine I, Constantine the Great, or (among Eastern Orthodox and Eastern Catholic Christians) Saint Constantine was proclaimed augustus (Roman emperor) by his troops, and ruled an ever-growing portion of the Roman Empire until his death.
Constantine is best remembered in modern times for the so-called Edict of Milan in January 313, which fully legalized Christianity in the empire for the first time, and the Council of Nicaea in 325, which he chaired. A previous edict of toleration had been recently issued by the emperor Galerius from Serdica and posted up at Nicomedia on 13 May 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 the Edict of Milan was signed. The Christians’ meeting places and other properties were to be returned:
…the same shall be restored to the Christians without payment or any claim of recompense and without any kind of fraud or deception…
The church could now own land, Christians could worship openly, and imperial patronage resulted in the affirmation of a single creed. However, now that bishops had imperial support, those who dissented from the dominant concept of orthodoxy or othopraxis could be punished. Thus, Christianity was changed from a fairly loose and diverse body of believers into a orthodoxy based on a uniform faith with a disciplined hierarchical institution on the Roman pattern.
Previously reluctant to engage in military action, Christians now joined the army and reconciled violence with their faith. Once Christianity became established as the state religion in the years following Constantine, the state began to impose Christianity on everyone and to persecute dissent, just as it had once persecuted Christians before Constantine’s conversion. Ironically, Christian leaders wasted no time taking advantage of their power to punish heretics, pagans, and Jews, now backed by the coercive power of the state.
When Constantine said “In hoc signo vinces” (“In this sign we conquer”), he wasn’t kidding.