According to Stark, the growth rate of Christianity did not change under its first Christian emperor in the 4th century (more than normal regional fluctuations). However, since Stark describes an exponential growth curve, he adds that it was “probably a period of `miraculous` growth in absolute numbers.” [115] By mid-century, it was likely that Christians constituted slightly more than half of the empire`s population. From Bononia, they crossed the English Channel into Britain and went to Eboracum (York), capital of the province of Britannia Secunda and home to a large military base.[110] Constantine was able to spend a year with his father in northern Britain and campaign against the Picts beyond Hadrian`s Wall in the summer and autumn. [82] The campaign of Constance, like that of Septimius Severus before, may have penetrated far north, without much success. Constantius was seriously ill during his reign and died on 25 July 306 in Eboracum.[83] Before his death, he declared his support for the elevation of Constantine to the rank of Augustus in his own right. The Alemannic king Chrocus, a barbarian commissioned under Constantius, then proclaimed Constantine Augustus. The troops, faithful to the memory of Constance, followed him in acclamation. Even if one doubts the exact veracity of these incidents, the claim that Martin preferred nonviolent conversion techniques speaks volumes about the standards of conversion in Gaul” when Sulpicius Severus, who knew Martin, wrote Martin`s biography. [253] On the obverse of this coin from 327 AD.

Constantine is turned to the right, with a diadem of three ribbons of pearls, his eyes raised especially towards the sky. This is markedly different from all other depictions of Roman emperors on coins and is directly related to the legend associated with his conversion to Christianity. According to his self-proclaimed biographer Eusebius, Bishop of Caesara, Constantine was on campaign in 312 AD when, around noon, he saw a cross of light shining on the sun with the text “by this conquest” (Blume 2012). This image, a combination of the Greek letters chi (X) and ro (P), has become one of the most widely used symbols for Christianity. In the years that followed, Constantine gradually consolidated his military superiority over his rivals in the ruined tetrarchy. In 313, he met Licinius in Milan to secure their alliance by marrying Licinius and Constantine`s half-sister, Constantia. During this meeting, the emperors agreed on the so-called Edict of Milan,[210] which officially granted full tolerance to Christianity and all the religions of the empire. [211] The document had particular advantages for Christians in that it legalized their religion and granted them restitution of all property confiscated during Diocletian`s persecution. It rejects earlier methods of religious coercion and uses only general terms to designate the divine sphere – “divinity” and “supreme divinity”, summa divinitas. [212] However, the conference was interrupted when Licinius received news that his rival Maximinus had crossed the Bosphorus and invaded European territory. Licinius gave up and eventually defeated Maximinus and took control of the entire eastern half of the Roman Empire.

Relations between the two remaining emperors deteriorated when Constantine was assassinated by a figure whom Licinius wanted to elevate to the rank of Caesar; [213] Licinius, for his part, had the statues of Constantine destroyed at Emona. [214] In 314 or 316, the two Augusti clashed at the Battle of Cibalae, with Constantine victorious. They clashed again at the Battle of Mardia in 317 and agreed on a settlement in which Constantine`s sons, Crispus and Constantine II, and Licinius` son, Licinianus, were made Caesars. [215] Under this arrangement, Constantine ruled the dioceses of Pannonia and Macedonia and settled in Sirmium, from where he was able to wage war against the Goths and Sarmatians in 322 and against the Goths in 323, defeating and killing their leader Rausimod. [213] Christians have suffered sporadic and localized persecution over a period of two and a half centuries.