As emperor, he made Christianity the official religion of the Roman Empire.
Christianity did eventually become the official religion of the Roman Empire.
Little headway was made in the countryside, however, until the late 4th century, by which time Christianity was the official religion of the Roman Empire.
Christianity was adopted as the official religion of the Roman Empire and enforced upon the Egyptians.
It was not until Theodosius I in the latter 4th century, however, that Christianity would become the official religion of the Roman Empire.
How did Christianity succeed in becoming the religion of the Roman Empire?
In 380, mainstream Christianity-as opposed to Arianism-became the official religion of the Roman Empire.
At any early date, Christian abbreviations were found side by side with those traditionally used in connection with the religions of the Roman Empire.
Before Christianity became the official religion of the Roman Empire, local Christians were being persecuted by the Romans.