SOFRONIUS, bishop of Pompeiopolis. — Omeusian bishop of the 4th century. According to the known catalogues of Michel Le Quien, S. would be the first known bishop of Pompeiopolis.
Already in 341, during the Council of Antioch, he had distinguished himself by his ardent defence of the term ὁμοιοῦστος to designate the consubstantiality of the Son with the Father. He would also have written a pamphlet which he sent to the emperor Constantius. The history of the councils records his name among the champions of semi-Arianism or alongside that of Silvanus of Tarsus, with whom he led the legation that disputed against the Acacians before the emperor Constantius; he subscribed to the letter to the deputies of Rimini and was present at the Synod of Constantinople (360; Theodoret, Hist. eccl., II, 23). His exclamation is well known, during the Council of Seleucia (359), against the assertions of Acacius: «If the strengthening of the faith consisted in allowing each person to express every day a personal opinion, every certainty of the truth would fall». He returned to his see after the death of Constantius and took part in several synods of Omeusians, whose doctrine he extolled as the only true one amid the excesses of the Westerners, who would have confused the persons of the Holy Trinity with their «consubstantiality», and of the Easterners who taught that the Son is unlike the Father (Socrates, Hist. eccl., V, 14).