Historical Development of the Trinity Doctrine – Fifth Century Arianism
The religious preferences of the Roman Emperors determined the Christology of the church. Emperor Constantine had a huge role in the formulation of the Nicene Creed. During the next 50 years, the emperors Constantius and Valens enforced Arianism. In 380 Theodosius became emperor and immediately outlawed Arianism. In the fifth century, Arian Germanic immigrants dominated the Western Empire and the West was Arian once again. But they tolerated the Roman Church and it actually grew in strength.