ossius) (c.256-357. Bishop of Cordova. Born in Spain, he was probably already bishop when he suffered persecution under Maximianus Herculius, before the edicts of Diocletian in 303. He was present at the Synod of Elvira (c.300) and was later in attendance on Constantine. The Donatists* blamed their condemnation by the emperor in the Council of Milan (316) to his being advised by Hosius. As sole master of the by 323, Constantine sent Hosius as his commissioner to Alexandria to settle the dispute between Alexander and Arius. Apart from refuting the dogmas of Sabellius it is not clear what he achieved; probably on his advice the emperor called the to settle the still unsolved Arian problem.
The role of Hosius in the council has been much discussed. He appears to have presided, but not as papal legate. His influence over the emperor can probably be seen in the latter's explanation of the Homoousion and letter to the churches concerning the council. After Nicea, Hosius appears to have returned to his diocese, but reemerged again in 345 at the. Constans, at the instigation of certain bishops, persuaded Constantius to call the council chiefly to settle the question of the orthodoxy of Athanasius. Athanasius traveled to Sardica with Hosius, who was to preside. When the Eastern bishops arrived, they refused to attend because of Athanasius's presence, and withdrew to issue an encyclical letter condemning Hosius and Julius of Rome and others for holding communion with Athanasius.
In 355 Hosius was summoned to Milan by Constantius to condemn Athanasius and to hold communion with the Arians. He refused, and persisted despite imperial persuasion. His only extant letter, a reply to Constantius, belongs to this period. Finally at Sirmium he was forced to sign the second (the “Blasphemy”) of the three creeds that seem to have emanated from here over this period (351, 357, 359). This was an Arian creed which Hosius probably repudiated before his death soon afterward in Spain. He has been described as dictatorial, harsh, and inflexible, and some of the blame for the failure of the Council of Sardica must rest on him. On the other hand, he was held by Athanasius and by Liberius of Rome in the highest honor.