section_path: History/Nicaea to East–West Schism (325–1054)
section_name: Nicaea to East–West Schism (325–1054)
paragraph_text: Nicaea to East–West Schism (325–1054)
  
  The Edict of Milan in 313 granted freedom to all religions in the Roman Empire, beginning the Peace of the Church. In 325, the First Council of Nicaea condemned Arianism, declaring trinitarianism dogmatic, and in its sixth canon recognized the special role of the Sees of Rome, Alexandria, and Antioch. Great defenders of Trinitarian faith included the popes, especially Liberius, who was exiled to Berea by Constantius II for his Trinitarian faith, Damasus I, and several other bishops.
  
  In 380, the Edict of Thessalonica declared Nicene Christianity to be the state religion of the empire, with the name "Catholic Christians" reserved for those who accepted that faith. While the civil power in the Eastern Roman Empire controlled the church, and the patriarch of Constantinople, the capital, wielded much power, in the Western Roman Empire, the bishops of Rome were able to consolidate the influence and power they already possessed. After the fall of the Western Roman Empire, barbarian tribes were converted to Arian Christianity or Nicene Christianity; Clovis I, king of the Franks, was the first important barbarian ruler to convert to the mainstream church rather than Arianism, allying himself with the papacy. Other tribes, such as the Visigoths, later abandoned Arianism in favour of the established church.
  
  The Edict of Milan in 313 granted freedom to all religions in the Roman Empire, beginning the Peace of the Church. In 325, the First Council of Nicaea condemned Arianism, declaring trinitarianism dogmatic, and in its sixth canon recognized the special role of the Sees of Rome, Alexandria, and Antioch. Great defenders of Trinitarian faith included the popes, especially Liberius, who was exiled to Berea by Constantius II for his Trinitarian faith, Damasus I, and several other bishops.
  
  In 380, the Edict of Thessalonica declared Nicene Christianity to be the state religion of the empire, with the name "Catholic Christians" reserved for those who accepted that faith. While the civil power in the Eastern Roman Empire controlled the church, and the patriarch of Constantinople, the capital, wielded much power, in the Western Roman Empire, the bishops of Rome were able to consolidate the influence and power they already possessed. After the fall of the Western Roman Empire, barbarian tribes were converted to Arian Christianity or Nicene Christianity; Clovis I, king of the Franks, was the first important barbarian ruler to convert to the mainstream church rather than Arianism, allying himself with the papacy. Other tribes, such as the Visigoths, later abandoned Arianism in favour of the established church.