When Did Christianity Become the Official Religion of the Roman Empire?

Updated: January 10, 2023
The Emperor Constantine I issued the Edict of Milan in 313, which provided for freedom of religion for all religions in the Roman Empire. Christianity became the official religion of the empire in 380 under Emperor Theodosius I.
Detailed answer:

In 313 AD, Constantine I (272-337) issued an imperial edict that granted toleration to Christians and their church leaders, provided they did not disturb public order. The edict was issued in Milan, Italy where Constantine had set up his capital after defeating Maxentius at the Battle of Milvian Bridge (312). It contained two important provisions: firstly, it established religious liberty for all Christians; secondly, it allowed them to build churches where they wanted.

By the time of Constantine’s reign, Christianity had already spread through much of the Roman Empire and beyond. However, it was still a minority religion in most areas.

Constantine’s conversion to Christianity came at the end of a long process that began with his victory over Maxentius at the Battle of Milvian Bridge in 312 AD and his subsequent victory at the Battle of Carthage in 312 AD against his rival for control of North Africa. Constantine later attributed these victories to God’s favor and declared himself an emperor “by the grace of God.” He then instructed his soldiers to mark their shields with an “inscribed” Chi-Rho symbol (the first two letters of Christ) in order to distinguish themselves from those who were not Christian.

When Did Christianity Become the Official Religion of the Roman Empire?. (2023, Jan 10). Retrieved from https://graduateway.com/qa/when-did-christianity-become-the-official-religion-of-the-roman-empire/