War Between Constantine and Licinius

By this course Licinius brought on himself the emperor Constantine’s heaviest displeasure, and they became enemies, for the pretended treaty of friendship between them had been broken. Not long afterward they took up arms against each other as open enemies. After several battles by sea and by land, Licinius was at last utterly defeated near Chrysopolis in Bithynia, a port of the people of Chalcedon, and he surrendered to Constantine. Constantine, having taken him alive, treated him with the greatest humanity and would by no means put him to death, but ordered him to settle at Thessalonica and live there in quiet. Licinius stayed quiet for a short time; but afterward he managed to gather some barbarian mercenaries and tried to make up for his recent disaster by taking up arms again. When the emperor learned what he was doing, he ordered that he be put to death, and this was carried out. [a]

So Constantine came to hold the sole rule and was accordingly proclaimed sovereign Autocrat, and once more he set about promoting the welfare of Christians. He did this in many ways, and through his efforts Christianity enjoyed unbroken peace. But an internal dissension soon followed this time of rest, and I will now try to describe its nature and origin.