Who Was Constantine, the First Emperor to Convert to Christianity?

FROM THE LECTURE SERIES: The Triumph of Christianity

By Bart D. Ehrman, The University of North Carolina, Chapel Hill

We have remarkably good documentation for Constantine’s life and far better documentation for his conversion to Christianity itself, than say, for the conversion of Paul. That’s not to say there are no historical controversies surrounding Constantine’s change of religious loyalties, quite the contrary.

An image of Church of the Holy Sepulchre in Jerusalem.
Helena did not establish the Church of the Holy Sepulchre even though people say she did. In fact, that was Constantine’s own doing after his conversion. (Image: Framalicious/Shutterstock)

Multiple Records of Constantine’s Conversion

Constantine’s own writings have come down to us from after the time of his conversion. There is also a written record of a number of laws that he passed and his complete biography, written by Eusebius. Eusebius was one of the leading Christian authors of his day and a historian. In addition, there are written accounts by other contemporaries who, like Eusebius himself, personally knew Constantine.

However, none of these records is problem-free. In fact, they often are at odds with one another. And experts debate a large number of issues central to the understanding of Constantine’s life, actions, motivations, and views. But, at least, we have written records that can help us adjudicate these disagreements.

In particular, there are three written reports, each produced by someone claiming to have heard the account of his conversion to Christianity from Constantine himself.

Constantine’s Early Life

Most of Constantine’s early life is shrouded in the mists of history. But there are some relatively certain facts. Constantine was born in the northern Balkans in 272 or 273 CE. That is, during the crisis of the 3rd century. He was born to a Roman military man, Constantius, who at the time was rising through the ranks of imperial power, and a woman named Helena.

Constantine was raised pagan, worshiping the local Balkan deities and eventually the gods of the Roman armies that he served in. As a young man, Constantine followed his father through the military and administrative ranks. When he was about 30, he became a junior officer in the court of the senior Augustus Diocletian, in the east, while his own father was the junior emperor in the west.

It’s hard to know what his parents’ relation to Christianity was. Many people have supposed that his mother, Helena, had become a Christian when Constantine was young, and that she had had an influence on his own conversion. There’s no good evidence of that, however.

Constantine’s Parents and Their Religion

An image of a sculpture. It depicts one of Mithras killing the bull in the Tauroctony, with Sol on the top left, recognisable by his flaming crown.
Constantius worshiped the god called Sol Invictus, the ‘Unconquered Sun’ more than the other pagan gods. (Image: Lalupa/Public domain)

It’s true that later in life, in her senior years, Helena had become a devout Christian convert. She was most famous for her pilgrimage to the Holy Land, where among other things, she established a couple of key churches. She did not, however, for the record, establish the Church of the Holy Sepulchre even though people say she did. In fact, that was Constantine’s own doing after his conversion. Nor did Helena claim to have discovered a piece of Jesus’s cross. That was only a later rumor.

Constantine’s father, Constantius, was also born and raised pagan. The Christian biographer Eusebius claims that Constantius had converted to the Christian faith before Constantine, but that appears to be wishful thinking on Eusebius’ part.

It does appear though, that Constantius may have become a pagan henotheist; one who worshiped one God as superior and more worthy than all the others. This may well have been the god called Sol Invictus, the ‘Unconquered Sun’. Apollo was often seen as the God of the Sun, and it may be that Constantius identified him that way.

This article comes directly from content in the video series The Triumph of Christianity. Watch it now, on Wondrium.

Constantine’s Vision and Conversion

A good deal of controversy surrounds Constantine’s religious history, in particular in connection with the Battle at the Milvian Bridge, when he recaptured Rome from Maxentius and became sole ruler of the city and the empire west of it. Sometime before the battle, Constantine experienced a vision, or a sequence of visions that led to his conversion.

As previously mentioned, we have three contemporary accounts of what happened, all written by people who had allegedly received the story from Constantine himself. These accounts have a number of things in common, but also some significant discrepancies. That’s not completely surprising since they were written by different people with different agendas, and 27 years apart.

A Panegyric in Honor of Constantine

One of these accounts is a speech that survives a panegyric in honor of Constantine, delivered by an unknown orator, in 310 CE, two years before Constantine’s march on Rome.

A panegyric was a common kind of speech in the Roman world that was designed to praise a person as one of the greatest human beings ever to have lived. This particular panegyric was delivered to celebrate Constantine’s victory in a major battle that had taken place in northeast Gaul, modern France.

In the speech, the orator indicates that Constantine had had a vision, in which the god Apollo promised him an extraordinary long life and indicated that he would become the sole ruler of the empire. It appears, based on the speech, that Constantine may well have devoted himself entirely to Apollo, Sol Invictus, the Unconquered Sun god at that point. That is, he may have become a henotheist like his father before him.

Eusebius’s Account

Another account, from 27 years later, is a much fuller account of Constantine’s conversion. It comes to us in a biography called The Life of Constantine by the Christian Eusebius, who is widely known as the father of church history. This is the account best known to people today.

According to Eusebius, who claims again to have received his information from the emperor himself, Constantine’s conversion occurred during his march to confront Maxentius in the battle for Rome. On route, Constantine saw a vision that changed everything. It sowed the seeds of Christianity in Constantine’s heart, a faith that though growing, was yet to receive imperial sanction.

Common Questions about Constantine, the First Emperor to Convert to Christianity

Q: How many written reports, pertaining to Constantine’s conversion, are there?

In particular, there are three written reports pertaining to Constantine‘s conversion.

Q: What is a panegyric?

A panegyric was a common kind of speech in the Roman world that was designed to praise a person as one of the greatest human beings ever to have lived.

Q: Who is known as the father of church history?

Eusebius is widely known as the father of church history.

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