Constantine and his Legacy

This Week in History

On yesterday’s date in 312 AD - 28 October - the Emperor Constantine defeated his rival emperor Maxentius at the Battle of the Milvian Bridge.

The night before the battle (Constantine later recounted), he saw a vision of a shining cross in the heavens inscribed "IN HOC SIGNO, VINCES": "BY THIS SIGN, CONQUER." The next morning, before the battle, he is said to have painted the sign of the cross on his soldiers' shields. And, after that, he did conquer - he won the battle, Maxentius drowned, and Constantine marched triumphantly into Rome. Shortly after, he issued the Edict of Milan which officially legalized and favored Christianity. Some years later, Constantine defeated his co-emperor Licinius and came to rule the whole empire; a few generations later, Christianity officially became the state religion it had already unofficially become.

After nearly a century of decline and civil war, it was clear to everyone that the Empire needed some new form of support. In the 200's, the Empire's population had permanently decreased by maybe a third, thanks to epidemics and climatic shifts making the Mediterranean less fertile.¹ Whole towns were abandoned, and philosophers said the world was getting old and wearing out. Amid this turmoil, huge civil wars broke out - nearly fifty years of near-constant war. People saw all this as divine disfavor. In response, the Imperial government imposed a single law code and direct Imperial prefects and judges over every province and city. Also, more importantly (to them), they tried to establish one single Imperial faith rather than the vague coexistence of local pagan gods. In the 250's, Emperor Decius had mandated for the first time that all subjects were compelled to sacrifice to the Emperor. Later in 274, Aurelian had tried to establish the worship of Sol Invictus across the Empire. In 300, Diocletian temporarily ended the civil wars. For the first time, he took direct control of large parts of the economy, even down to a list of mandated prices. And, he tried again to exterminate Christianity. Diocletian's persecution was the greatest persecution yet; for a while, some churches even dated their chronology from it in "The Era of the Martyrs." But after Diocletian's abdication, another civil war broke out (which lasted until Constantine's victory) - and Christianity kept growing.

Modern scholars are still debating just how many Christians there were in the Empire. Perhaps the best-justified model is by Rodney Stark, in his excellent book The Rise of Christianity. He models a constant growth rate from Pentecost (when Christianity began) through Constantine's reign, and concludes that in 300 AD, about ten percent of the Roman Empire were Christians. There were more than ten percent in the cities, and less in the rural areas. But, that had grown from only about two percent in 250... which lines up with how we see the Roman government suddenly seeing Christians as a significant force (and, for example, Diocletian's launching the unprecedentedly-large Great Persecution). So, when Constantine invoked Christianity - he was facing an Empire with maybe one out of ten people Christian, concentrated in the (visible) cities. So, by cynical political standards, his decision wasn't outlandish. Christianity was a significant and growing force - it was still a minority, but one which there could be political advantage in favoring.

Now, Constantine embraced Christianity. It was a shrewd political move to ally himself with this new, constantly-growing force.² Perhaps it was political calculation, or perhaps he saw something that he interpreted as a vision. Or perhaps he saw a real vision - as a Christian myself, I'm not going to exclude that possibility. I don't say he became a Christian himself at the Milvian Bridge; for years later, he still sometimes invoked the pagan gods and used pagan imagery. (He also delayed baptism till his deathbed, but that’s not relevant since it was a common practice among Christians at the time.) Regardless, this reversal from persecution to encouragement paid off: Constantine became the first unchallenged ruler of the whole empire in decades.

Suddenly going from persecution to imperial favor greatly changed the Church. Now, bishops were being showered with lavish gifts, and rich people were clamoring for church offices. As Peter Brown explains in his extremely detailed Through the Eye of a Needle: Wealth, the Fall of Rome, and the Making of Christianity in the West, this opened new opportunities but also presented new temptations... and all too often, the Church fell for them, currying favor with the upper classes and appointing rich people's sons as priests and bishops.

Even aside from the influx of upper-class Romans he prompted, Constantine himself pulled the Church in directions it seemed he didn't really understand. He encouraged the flood by giving bishops privileges of magistrates. He sponsored favored ecclesiastics at his court, commissioning Eusebius of Caesaria to write a church history. And - perhaps most notably - he summoned the Council of Nicaea to settle the Arian controversy over whether Jesus was really fully God.³ Constantine pled for a compromise that would unite everyone, in words that would be familiar to any pagan. But to their credit, the bishops explained that doctrine did matter to Christianity. Constantine would vacillate for years on whether to accept the Nicene Creed; Bishop Athanasius would be repeatedly exiled for unrelentedly defending it. Eventually, the Church would hail Nicaea as a great triumph - but in the short term, it looked like a failure.

In the end, Christianity did uphold the Empire. In the West, the Empire lasted another century and a half before the last Roman emperor was deposed by the barbarian leader commanding the imperial army. The legacy of Rome continued for centuries, but the Empire had fallen in the West. But in the East, the Empire reinvented itself around Constantine's new-built capital of Constantinople and Constantine's new-adopted faith of Christianity, and lasted more than eleven hundred years after Constantine. Perhaps it lasted even longer - one could argue that the Ottomans were a continuation of the same Roman Empire (they reigned from Constantinople and used "Caesar of Rome" as one of their secondary titles), in which case the Roman Empire lasted another four and a half centuries till 1921.

That was, probably, what Constantine cared about the most. But at least two other things lasted as well.

The Council of Nicaea served as a precedent for the idea of church councils settling doctrinal disputes. Over the centuries - down to the Second Vatican Council in 1962 - ecumenical councils would be summoned, by the Emperor or (eventually) by the Pope, to settle questions of doctrine and discipline. Eventually, it would be decided that a true ecumenical council is infallible when it makes statements of doctrine. Constantine had no idea he was setting this precedent when he summoned the Council of Nicaea, but it does date back to him.

In a less savory way, Constantine's interference with church government also lasted as a precedent for the Emperor interfering with the church. In the West, a counter-precedent was set in 1076 when Pope Gregory VII excommunicated Emperor Henry IV and got away with it. But in the East, the Emperor regularly appointed the Patriarchs of Constantinople and forced them to resign. The Iconoclast Controversy of the 700-800's wasn't totally settled by the emperors, but it did ebb and flow with the emperor's leanings. And then, this set a precedent for the Ottoman and Russian empires to govern the church in their dominions even more strictly. Constantine didn't come close to causing all this, but he did set the precedent that led to it.

Eusebius concludes his history saying, "Thus after all tyranny had been purged away, the empire which belonged to them was preserved firm and without a rival for Constantine and his sons alone." And indeed, Constantine had reinvented the Empire; a new age dawned with him. It was not the age he planned out or hoped for; history (and, Eusebius would say, God) twisted his legacy down paths he didn't expect. I can hardly blame Constantine for the bad aspects of his precedents; his main fault there was ignorance. But at the same time, I would praise him for re-founding the Empire as an idea that would last.

Constantine had himself buried amid relics of the Twelve Apostles, as if he thought himself a thirteenth apostle. That, I would say, was thinking too highly of himself. But if any man of his era had a legacy, it was Constantine.

1. For a good survey of the climatic shifts and plague, see The Fate of Rome, by Kyle Harper.

2. There's a later tradition that Constantine’s mother Helena had already been a Christian, but there’s no strong support for that. The contemporary historian Eusebius says she only became Christian after Constantine gained the throne.

3. Despite a popular myth, the Council of Nicaea didn't decide which books belonged in the Bible. Years before the Council, we have lists which all agree on most of the same books as today; years after the Council, Eusebius was still saying that a few books were disputed.