By Bart D. Ehrman, The University of North Carolina, Chapel Hill
In 305 CE, Diocletian decided to abdicate, the first Roman emperor to do so. He wanted his senior colleague in the west of the empire, Maximian, also to abdicate at the same time. Thus, the juniors, Galerius and Constantius, became the senior emperors in the east and the west, respectively. So, subsequently, were Constantine and Maxentius chosen purely on merit, under Diocletian’s Tetrarchy, the rule of four?
Maxentius Seizes Rome
The next year, as Constantius was suddenly dying, his junior, Severus, was to ascend to the senior role. The new junior emperor to replace Severus, was to be chosen based purely on merit and as per Tetrarchy, was not to be related to any of the other three ruling emperors. But, in a surprise move, prior to his death, Constantius appointed his own son, Constantine, for the position. That was a big problem, especially for sons of others of the emperors.
The original senior emperor of the west, Maximian, had a son, Maxentius, who, like most sons of emperors, wanted the imperial rule for himself. He was angry and jealous that Constantine had landed one of the four slots, but he had not. And so, Maxentius took matters in his own hands and seized imperial office, by seizing power over the city of Rome itself. He called himself an emperor and claimed that he was on an equal status with the other four. So now, the rule of four had five.
Over some years, the two senior emperors, Severus, in the west and Galerius, in the east, both unsuccessfully tried to dislodge Maxentius from his fortified city, the capital city Rome. One of them, Severus, the senior to Constantine, eventually died in the effort. He was not replaced.
Constantine and Maxentius’s Battle for Rome
Constantine then ruled the west alone and bided his time considering what to do about the usurper, Maxentius, in Rome. Finally, in 312 CE, he decided the time was right. Constantine marched his army across the Alps, made for Rome, and the city prepared for battle.
In anticipation of the assault, Maxentius made one rather sensible move. He had all the bridges across the Tiber that provided access to the city destroyed, but then he made a second decision that was disastrous. Instead of stealing the city for a siege, he decided to come out in force to face Constantine’s army in the field. But with the bridges out, there was no way to cross the Tiber, nor to favorable battle grounds.
Hence, Maxentius had a temporary pontoon bridge built next to the recently destroyed Milvian Bridge. He marched his army across it, and they engaged in battle. Constantine’s forces outmaneuvered him.
Maxentius’s soldiers were backed up against the river with no place to go. They desperately tried to cross the pontoons in a beeline for the city, but under the crushing weight the bridge collapsed. Many of the soldiers and Maxentius himself drowned in the Tiber. Constantine entered Rome the next day as its ruler and as the emperor of the entire western half of the empire.
This article comes directly from content in the video series The Triumph of Christianity. Watch it now, on Wondrium.
Constantine’s Victory Credited to the Christian God?
As significant as the military event was in the political history of Rome, there was another outcome that was far more significant for the history of the West, down to today. Constantine believed that it was the Christian God who had assisted him and had ensured his victory over Maxentius. He later claimed that it was on that day, October 28th, 312 CE, that he converted to become a Christian. The empire was never the same again.
It would be inaccurate to state that the conversion of Constantine is the single, or even the principal, reason the empire eventually became Christian. Even though that’s what a lot of people claim, but it’s probably not right.
On the contrary, Christianity was growing by leaps and bounds by his day and, at the rate it was going, it almost certainly would have taken over the empire, even if he hadn’t converted. In fact, the rate of conversion had to slow down significantly in his day, otherwise there would have been far more Christians in the world than people, by the end of the century.
Constantine’s Conversion
Another way to look at this, is that if things had continued on the way they were going but Constantine had not converted, one of his successors may well have done so, possibly one of his sons who later assumed the reins of the empire. It’s also not correct to think that Constantine’s conversion mattered because he went on then to make Christianity the official religion of the empire. That, in fact, is not true.
Constantine certainly did not do that or declare pagan religions illegal. It was not until closer to the end of the 4th century that an emperor made Christianity the official religion. That was the emperor Theodosius I.
Moreover, Constantine’s conversion was not significant because he used his imperial power to decide which books would be in the New Testament, as is often said. Or, that he was the one who ultimately decided that Christ should be considered the Son of God.
Offering Imperial Support to Christianity
The actual reason Constantine’s conversion is so significant is because he turned the imperial apparatus, that had tried to stamp out Christianity, into one that supported and promoted it. This made it easier for the Roman elite to convert. And, as they eventually came into the religion in droves, the pagan cults were more or less starved out of existence.
It may have happened anyway, but it happened now with imperial sanction and support, and the Roman world never seriously turned back.
Common Questions about Constantine’s Victory and Rome’s Conversion to Christianity
In a surprise move, prior to his death, Constantius appointed his own son, Constantine, for the position of the junior emperor.
Maxentius was angry and jealous that Constantine had landed one of the four slots, but he had not.
Constantine believed that it was the Christian God who had assisted him and had ensured his victory over Maxentius.
