High Quality Content by WIKIPEDIA articles! Arianism is the theological teaching attributed to Arius (ca. AD 250–336), a Christian presbyter in Alexandria, Egypt, concerning the relationship of God to the Son of God (Jesus of Nazareth). Arius asserted that the Son of God was a subordinate entity to God the Father. Deemed a heretic by the Ecumenical First Council of Nicaea of 325, Arius was later exonerated in 335 at the regional First Synod of Tyre, and then, after his death, pronounced a heretic again at the Ecumenical First Council of Constantinople of 381. The Roman Emperors Constantius II (337–361) and Valens (364–378) were Arians or Semi-Arians.