Arius was born in Libya. He studied theology in Antioch at the School of Lucian. He returned to Alexandria where he was ordained a deacon and then a priest. In 318, he started to preach his theological doctrine, which provoked many discussions. His main doctrine was that because the Son was the first creature of God, he is not from the same substance of the Father; hence, the Son is a son in a moral sense rather than a metaphysical sense. In fact, Arius’ teachings were another form of Subordinationism. A council convened in Alexandria under its patriarch, Alexander, condemned Arius’ heresy and excommunicated him. Arius tried to find allies from among his colleagues at the School of Antioch, such as Eusebius of Nicomedia.
Emperor Constantine convoked a council in Nicaea to discuss the matter. The council condemned Arius to exile, but Arius did not give up. He continued to pressure the bishops until he was reaccepted into the Church by the synods of Tyre and Jerusalem in 335. However, he died suddenly just one day before his official reintegration. The Athanasian party saw this event as divine vengeance. Arius was not a prolific writer. His teachings seemed to have largely been transmitted orally. According to Epiphanius of Salamis, Arius wrote a letter to his friend Eusebius of Nicomedia and a creed, which he presented to the Emperor Constantine. Some fragments were partly preserved in the writings of his opponents.