19 votes, average: 4.74 out of 519 votes, average: 4.74 out of 519 votes, average: 4.74 out of 519 votes, average: 4.74 out of 519 votes, average: 4.74 out of 5 (19 votes, average: 4.74 out of 5)
You need to be a registered member to rate this post.

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 earlier.  So too see the significance of that we have to consider what went before.

Diocletian had instituted the Tetrarchy because the empire was simply too massive for one person to govern, especially with constant threats (and realities) of barbarian invasions everywhere from Britain (across Hadrian’s wall),  to the northern Rhine and Danube borders (the rivers marked the north boundary of the empire), on to the East with the Persians.

So, as I indicated last time, Constantine’s father …

THE REST OF THIS POST IS FOR CARD-CARRYING MEMBERS ONLY.  If you don’t belong yet, BUY YOUR CARD!!!  It doesn’t cost much (and OK, there’s no actual card), and you get tons for your money!  And every dime goes to charity!!!

You need to be logged in to see this part of the content. Please Login to access.

How Constantine Became Emperor
The Emperor Constantine: Some Background



  1. Belasaurius
    Belasaurius  July 13, 2016

    Do you think the chaos of the third century worked to Christians advantage? That the Empire was busy with infighting and political instability that it Christianity was able to grow without serious challenges?

    • Bart
      Bart  July 15, 2016

      Yeah, I’ve pondered that, but I’m not sure it can be shown; it would be hard to show that hte *rate* of growth changed significantly, and this was the period when pagans started persecuting the church more. But maybe I’ll address the quesiton more fully in a Readers Mailbag.

      • Avatar
        Skolymos  July 17, 2016

        Professor Ehrman,
        I try to understand why Diocletian started the so called Great Persecution. Taking into consideration the Greco-Roman tolerance towards every religion, it is not easy for me to explain why he (and some other emperors before him) persecuted Christians in particular. Do we have any evidence that Diocletian cosidered them responsible for the chaotic situatation that preceded his ascension to power? In other words, had he any evidence/proof that Christians where not just another religion among the many in the empire, but that they were causing political turmoil with their theories and practices? If so, are there any historical sources that could help us to justify Diocletian’s decision to persecute them?

        • Bart
          Bart  July 18, 2016

          Yes, I hope to be getting to this eventually. Main point: there were strong reasons not to want the Ronman gods to become wrathful at the presence of such people in the Empire.

  2. Avatar
    marcrm68  July 13, 2016

    Power does have a way of corrupting absolutely… It was a game of king of the hill, and Constantine won…with the help of Jesus! But along the way, he murdered his wife and son! Jesus was the only one who could forgive his sin! It’s really pretty horrible…

  3. Avatar
    Boltonian  July 13, 2016

    Ah, I Claudius. I remember it well. It made the careers of some very (now) famous actors, although some were already quite well known at the time: Brian Blessed (Augustus); Stanley Baker (Tiberius); John Hurt (Caligula), Sian Phillips (Livia); Patrick Stewart (Sejanus); and the wonderful Derek Jacobi as Claudius. It is also worth reading the books by Robert Graves – in fact anything by Graves is interesting, including the novel, ‘King Jesus,’ which is his attempt to portray the life of the historical Jesus.

    I agree that there weren’t many good emperors; you mentioned one, Marcus Aurelius, and I would offer a couple more: Hadrian and Trajan. I would also add that in the big picture Vespasian and Titus provided much-needed stability after the madness of Nero and the turmoil of that ‘that long but single year.’

    Constantine, BTW, was an army commander just down the road from here in York, where there is a statue of him outside the Minster.

  4. Avatar
    Jason  July 13, 2016

    Didn’t Caligula have one son, but more in the way that one “has” a hamburger?

    • Bart
      Bart  July 15, 2016

      He had an adopted son (whom he executed), but I don’t know that he had a birth-son.

      • Avatar
        Jason  July 16, 2016

        So the episode where he imitates Zeus by eating the unborn child from his sister’s womb was another of Graves’ “theories?”

        • Bart
          Bart  July 17, 2016

          There were numerous nasty rumors about him in circulation; I can’t remember off the top of my head whether that one was in Suetonius or not (I’m away from my books and can’t check!)

  5. Avatar
    Hank_Z  July 14, 2016

    Good info, but the post didn’t do what the first sentence promised.

  6. Avatar
    KathleenM  July 14, 2016

    As I remember Constantine had a really great Mom, who did a lot for future Christians, and he granted her a trip to the Holy Land where she built the first dome over the Holy Sephlucre (sp?) that is all being revamped and dug up a bit currently. (The Franciscans do a lot of work in the Holy Land today, Nazareth also. Some were even martyred over the years, guarding the sites. I’m sure Francis loves all this work today as it was one of his loves and he spent some time there during his life.) Like Augustine had his Monica, Constantine had his Helena. Constantine was finally baptized after he retired, as he feared prior to that he might have to “murder” someone, as sure enough he did take out some of his relatives. The early Christian woman had a lot of sway with other women and thus their husbands and families as well. St. Monica did abuse counseling with the soldiers wives during her life.

    Caligula had a high fever of 104 or 106 I think Josephus or someone recorded, he was expected to die, but rose up from his sick bed, but was then crazy for the rest of his life. Other Romans had that town water with lead added, plus the leaded wine, so I think a lot of the men went crazy, whereas maybe Marcus Aurelius and some of the women probably didn’t drink so much, or lived outside the city more? Now today we have Alzheimer’s and Mad Cow and other forms of brain “tangles”, attention deficit disorders. Looking back someone will see what we are doing to ourselves – various food “additives” for flavor, etc.

    The Roman Empire eventually went to be ruled by the highest bidder, the Emperor’s seat was sold to whoever could pay for it!!! No one wanted to govern. (Similar to today also–the richest campaign the most.) I liked the Persians and Assyrian Empire in some ways better – Cyrus was a wise king, of course he had Esther and Mordecai as advisors – Cyrus was more libertarian like the early Egyptians, who didn’t keep hardly any slaves really–war captives were freed as they aged, seen to have allegiance to the Pharoah. The first pyramids were built in coop with people from other countries. We still have the cylinder seals sent out to other kingdoms by chariot: “Hi from Egypt. Plan: building to the sky. Will call it a pyramid. Would you like to send workers? Feed well, sleep well, good times, just let me know. We need labor, architects, etc. How is the wife and family?” All very civil. The first one flopped, so they sent out for more crews and the 2nd one succeeded with the continued group effort.

  7. Avatar
    RonaldTaska  July 14, 2016

    Sounds sort of like the recent Republican campaign for president, a free for all.

  8. Avatar
    Scott  July 14, 2016

    What a delight to enter into an era about which I know next to nothing.

  9. Avatar
    JackBakewell  July 15, 2016

    Does Constantine have anything to do with the development of the Roman Catholic church, or was that earlier?

    • Bart
      Bart  July 17, 2016

      When he accepted Christianity, it was the Roman form of Christianity, and that obviously helped promote the cause of Roman Christianity, which became Roman Catholic Christianity eventually.

      • Avatar
        JackBakewell  July 17, 2016

        Oh ok. Roman Catholics claim that the Roman form Christianity goes right back to Jesus’ disciples. Is there any truth to this?

        • Bart
          Bart  July 18, 2016

          Sure — but then again, every form of Christianity ultimately does!

          • Avatar
            JackBakewell  July 18, 2016

            Well yes. But do you think that Jesus’ disciples would recognise the Catholic Church as the institution created by their leader, were they around today? In other words, does the claim that the Catholic Church is the one true Church of God have any historical credibility?

          • Bart
            Bart  July 19, 2016

            No, I don’t. But they wouldn’t recognize any of the modern forms of Christianity.

          • Avatar
            HawksJ  July 19, 2016

            In response to JackBakewell above, you comment:
            “No, I don’t. But they wouldn’t recognize any of the modern forms of Christianity.”

            This raises a fascinating point, I think. There are a number of
            ‘denominations’ that believe that they practice true ‘1st Century Christianity’ (even though each, by definition, interprets what that means in a different way).

            From a HISTORICAL standpoint, it would, indeed, be fascinating to learn what the very earliest ‘church’ and ‘worship service’
            (for lack of better phrases) looked like. Or, at least, what can be said about the earliest ‘church’ and earliest ‘services’?

          • Bart
            Bart  July 20, 2016

            You might want to look at the books by Paul Bradshaw on ealry Christian worship.

You must be logged in to post a comment.