Arius

Arius (c. 250 or 256–336) was a presbyter of the Baucalis district in Alexandria whose teaching that the Son of God was a created being — subordinate to and ontologically distinct from the Father, existing "before times and before ages" but not co-eternal — provoked the most consequential doctrinal crisis of early Christianity. His views were disseminated through the poetic-prose work known as the Thalia and through a network of episcopal supporters across the eastern empire. The First Ecumenical Council of Nicaea (325) condemned his teaching as heresy and exiled him to Illyricum, though subsequent imperial politics led to his partial rehabilitation before his sudden death in Constantinople in 336. His writings survive only in fragments, mostly as quotations preserved by his opponents, and the tradition that bears his name, Arianism, shaped Christian theological controversy for centuries after his death.