**HOSIUS (Ossius) OF CORDOVA.** – Born c. 257, died c. 358. He first appears at the Council of Elvira (c. 300), bishop of Cordova from 295; a confessor of the faith during the persecution of Diocletian and Maximian in 303, he was able to display his glorious scars at Nicaea. From 313 he was an advisor to Constantine, in whose conversion he may have played a principal part. Subsequently, his life became identified with the cause of orthodoxy against Arianism. Invited by Constantine to Alexandria (c. 324), he convened a council there which rejected the doctrine of Sabellius. The schism of Colluthus was also condemned there. More decisively, O. prepared together with Constantine the celebration of a general council at Nicaea to definitively condemn Arius. He presided over its sessions as president, alongside the Roman legates, and promulgated in it the formula of *homoousios* as the touchstone of orthodoxy.
The personal, though not exclusive, collaboration of O. in the drafting of the Nicene Creed seems undeniable. He also presided over the Council of Sardica (343), and its canons and a letter to Pope Julius I regarding the Nicene Creed are attributed to him.
O. intervened in other grave matters as well. The Donatists attributed to him the severe imperial decrees of 316, occasioned by the schism against Bishop Cecilian. The Emperor’s law of 18 April 321, which facilitated the manumission of slaves in churches, was addressed to O. (Cod. Theod., 4, 7): a clear indication of the role he played in II.
For a long time O. resisted the pressures of Constantius (355), who sought to make him renounce the faith of Nicaea and condemn St. Athanasius. His energetic reply (356) earned him exile in Sirmium at the hands of the Emperor; and there, now a centenarian, worn out by hardships and exile amid every kind of violence, he was finally forced to sign the second formula of Sirmium, which he soon retracted at the hour of his death, as forcibly imposed; thus St. Athanasius attests: «In his testament he protested against the violence used and hurled his anathemas against Arian heresy, ordering that no one follow it.» The Greek Church venerates him as a saint on 27 August.
His entire life was devoted to action. He left behind, though brief, some writings, true literary gems. St. Isidore of Seville attributes to him a letter to his sister, *De laude virginitatis*, in serene style, and a treatise *De interpretatione vestium sacerdotalium quae sunt in Veteri Testamento*, whose ingenuity and prudence he praises; but nothing of these works has been preserved. St. Athanasius, however, transmitted in his *Historia Arianorum*, 44, the letter to Constantius, a monument to the fortitude of the great bishop, and at the same time a decisive canon on the jurisdiction and immunity of the Church before every kind of abuse.