Preface to Constantine: The Rule of the Four
In this post I want to explain how Constantine came to power. It is an unusually complicated story, with all kinds of names and dates that only inveterate historians could love. I’ll give a simple version of it here, more suitable for those of us who are mere mortals. The reason it matters is that Constantine’s predecessor’s Diocletian vision of a Tetrarchy (= Rule of Four), in which the empire would be ruled by two senior emperor (each called an Augustus) and two junior emperors (each called a Caesar), with one pair (senior – junior) in the East and one in the West, didn’t last past a year after Diocletian’s abdication. There were usurpations, infightings, civil wars, and a whole mess of things for years until Constantine emerged as the sole ruler of the Empire. He was in power (first as a ruling partner, then as the one guy at the top) for over thirty years, longer than any ruler of the empire apart from the one who started it all, Caesar Augustus, three centuries [...]