Christianity in the 4th century

Christianity in the 4th century was dominated in its early stage by Constantine the Great and the First Council of Nicaea of 325, which was the beginning of the period of the First seven Ecumenical Councils (325–787), and in its late stage by the Edict of Thessalonica of 380, which made Nicene Christianity the state church of the Roman Empire. == Christian persecutions == With Christianity the dominant faith in some urban centers, Christians accounted for approximately 10% of the Roman population by 300, according to some estimates.

Source: Wikipedia — Christianity in the 4th century (CC BY-SA 4.0)