Church History · AD 312 to 313

Constantine and the Edict of Milan

In 312 Constantine won the Battle of the Milvian Bridge after a vision of a heavenly sign, and in 313 he and Licinius agreed to the Edict of Milan, giving Christians freedom to worship. Christianity became legal, but it did not become Rome's official religion until 380.

Read it in the Bible: John 18:36 Romans 13:1 Mark 12:17

On October 28, AD 312, Constantine defeated his rival Maxentius at the Milvian Bridge outside Rome, after reporting a vision of a heavenly sign tied to Christ. A few months later, in 313, he and the eastern emperor Licinius agreed on a policy we call the Edict of Milan. It gave Christians and everyone else freedom to worship and returned church property taken during the persecutions. Christianity went from hunted to legal almost overnight. It did not, however, become the official religion of Rome. That came in 380.

Who Was Constantine?

Constantine was born around 272 in what is now Serbia. His father, Constantius, ruled the western part of the empire and was fairly easy on Christians. When his father died in 306, the army in Britain declared Constantine emperor. Several men claimed the throne at once, and the next 18 years were a long game of thrones.

By 312 Constantine controlled Gaul and Britain. Maxentius held Rome and Italy. Constantine marched on Rome with a smaller army.

What Happened at the Battle of the Milvian Bridge?

Maxentius came out of the city to fight near the Milvian Bridge over the Tiber River. His lines broke, and as his army retreated across a temporary bridge, it collapsed. Maxentius fell into the river and drowned. Constantine entered Rome the next day as master of the West.

Constantine gave the credit to the God of the Christians. From then on he openly favored the church, though he kept the pagan title of chief priest for the rest of his life.

Did Constantine Really See a Cross in the Sky?

We have two main accounts, and they don't match perfectly.

Lactantius, a Christian teacher at Constantine's court, wrote about 315 that Constantine had a dream the night before the battle. He was told to mark the heavenly sign of God on his soldiers' shields. The sign seems to have been a cross with a loop at the top, an early Christian symbol.
Eusebius, bishop of Caesarea, wrote the Life of Constantine after the emperor died in 337. He says Constantine told him, under oath, that he and his army saw a cross of light above the sun with the words, By this, conquer. The Latin version is in hoc signo vinces. That night, Christ appeared to him in a dream and told him to use the sign as protection.

The sign is often called the Chi Rho, the first two Greek letters of Christ, X and P, laid on top of each other. Constantine later put it on his army's standard, called the labarum, and on coins. Historians debate what exactly he saw. Some think it was a dream, some a natural sun halo, and some a real miracle. What we know is that Constantine believed God had given him the victory.

What Did the Edict of Milan Say?

In February 313, Constantine met Licinius in Milan. They agreed on a religious policy for the whole empire. The text we have is a letter Licinius posted in Nicomedia on June 13, 313. Lactantius and Eusebius both preserve versions of it.

It said:

Christians, and everyone else, were free to follow whatever religion they chose.
Church buildings and property seized during the persecutions had to be returned.
The government would pay the people who had bought that property.

Notice what it did not say. It did not make Christianity the state religion, and it did not ban paganism. Technically it was a letter of policy, not a formal edict, but the name stuck. The Persecution page on this site explains what Christians had just come through, which is why this felt like a miracle.

When Did Christianity Become the Official Religion of Rome?

Not under Constantine. A lot of people mix this up. Constantine made Christianity legal and gave it money, buildings and favor. He built the first St. Peter's in Rome and the Church of the Holy Sepulchre in Jerusalem. In 321 he made Sunday a day of rest for courts and city workers. In 325 he called the Council of Nicaea.

But paganism stayed legal. Christianity became the official religion of the empire in 380, when Emperor Theodosius I issued the Edict of Thessalonica. That story has its own page on this site.

Was Constantine a Real Christian?

This is one of the big debates in church history. Here are the two sides fairly put.

The skeptical view notes that he kept pagan titles, his coins showed the sun god for years, and he had his own wife and eldest son executed in 326. He also waited until he was dying to be baptized in 337. Some see a shrewd politician who backed the winning team.

The sympathetic view notes that late baptism was common then, because people believed baptism washed away past sins. He spent huge sums on the church, wrote letters full of Christian faith, and stuck with it even when it cost him. Most historians today think his faith was real, even if it was mixed with the habits and harshness of a Roman emperor.

The Bible reminds us that only God sees the heart. What is clear is that his reign changed the church forever, for good and for bad. Persecution ended. But the church also gained power and money, and later leaders sometimes used the state to force belief.

Why Constantine Matters for You Today

Constantine's story is a reminder that God can turn history in a day. For 250 years Christians had been jailed and killed. Then, almost suddenly, they could build churches in the open.

It is also a warning. The church grew strongest when it had no power at all, only the gospel. Jesus never needed an emperor to build His kingdom.

Jesus answered, “My kingdom is not of this world; if it were, My servants would fight to prevent My arrest by the Jews. But now My kingdom is not of this realm.” John 18:36

Whether a government favors the church or fights it, our job is the same: trust Jesus, love people and keep telling the good news.

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Questions People Ask

What did the Edict of Milan do?

The Edict of Milan, agreed by Constantine and Licinius in 313, gave Christians and all other religions freedom to worship. It also ordered that church property seized during the persecutions be returned. It made Christianity legal, not official.

Did Constantine make Christianity the official religion of Rome?

No. Constantine legalized and favored Christianity, but paganism remained legal during his reign. Christianity became the official religion of the empire in 380 under Theodosius I, through the Edict of Thessalonica.

What did Constantine see before the Battle of the Milvian Bridge?

According to Eusebius, Constantine said he saw a cross of light above the sun with the words By this, conquer, followed by a dream in which Christ told him to use the sign. Lactantius describes only a dream telling him to put a heavenly sign on his soldiers' shields. Historians still debate what he actually experienced.

When was Constantine baptized?

Constantine was baptized shortly before his death in May 337, near Nicomedia. Delaying baptism until near death was common at the time, because people believed baptism washed away all earlier sins.

Sources

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