(d. 336), heresiarch.
Probably born in Libya between c.260 and 280, he was ordained in Alexandria and put in charge of one of the main churches there. About 319 he came forward as a champion of subordinationist teaching about the Person of Christ; he was condemned by a Council at Alexandria and excommunicated. The Council of Nicaea (325) also condemned him. Owing to the influence at court of Eusebius of Nicomedia, he was recalled from exile probably c.334. He died suddenly in Constantinople. See also Arianism.