Arius, Greek Areios c.250-336AD
Libyan theologian, founder of the heresy 'Arianism'

Trained in Antioch, he became a presbyter in Alexandria and c.319AD maintained, against his bishop, that in the doctrine of the Trinity the Son was not co-equal or co-eternal with the Father, but only the first and highest of all finite beings, created out of nothing by an act of God's free will. He secured the support of clergy and laity in Egypt, Syria, and Asia Minor, but was deposed and excommunicated in 321 by a synod of bishops at Alexandria. Eusebius of Nicomedia absolved him, and in 323 convened another synod in Bithynia, which pronounced in his favour. At Nicomedia, Arius wrote a theological work in verse and prose, called Thaleida, some fragments of which remain. To settle the controversy the Emperor Constantine I, the Great called the Council of Nicaea (Nice), in Bithynia (325) with 318 bishops present, besides priests, deacons and acolytes. Arius boldly expounded and defended his opinions but the reasoning of Athanasius greatly influenced the Council to define the absolute unity of the divine essence, and the absolute equality of the three persons. Two dissenting bishops were banished along with Arius, who was recalled in 334, but was refused admission to church communion, fuelling the controversy in the East. In 336 Arius went to Constantinople (Istanbul), where he died suddenly, before he could be admitted to the sacrament. After his death the strife spread more widely abroad. The West was mainly orthodox, the East largely Arian or semi-Arian. There was a good deal of persecution on both sides and Arianism was at last virtually suppressed in the Roman Empire under Theodosius I, the Great in the East (379-95), and Valentinian II in the West. Among the Germanic nations, however, it continued to spread through missionary efforts and was revived in England by the philosophers Samuel Clarke and William Whiston, only to be superseded by Unitarianism.