Hosius (also written Ossius or Osius) was the long-serving Bishop of Córdoba in Roman Spain and one of the most influential churchmen of the fourth century. Born around 256, he was consecrated to the see of Córdoba about 295 and held it for more than sixty years. He is venerated in the Eastern Orthodox Church as a Confessor, commemorated on August 27, and is numbered among the pre-schism Western saints honored as Orthodox.
Hosius lived through the great transition from persecution to imperial favor. He narrowly escaped martyrdom during the persecution of Maximian in the early fourth century and took part in the provincial Council of Elvira in the first years of the century. After the conversion of Constantine the Great, he served from about 312 onward as an ecclesiastical adviser at the imperial court, and in 324 the emperor sent him to the East as his emissary to address the rising controversy over the teaching of Arius.
His name is bound above all to the First Ecumenical Council at Nicaea in 325, where his name stands first on the list of participants and tradition holds that he presided. He was a leading advocate of the term homoousios — that the Son is of one essence with the Father — which the council enshrined in the Creed against Arianism, and he was among the first to sign its acts. He maintained this stance at the Council of Sardica around 343, where he again held a foremost place and supported Athanasius the Great of Alexandria.
In extreme old age Hosius became a confessor in the strict sense of one who suffers for the faith without dying. Having protested imperial interference in the affairs of the Church, he was exiled by the emperor Constantius II to Sirmium around 355. There, under threats and physical violence, the centenarian bishop was coerced into subscribing to a non-Nicene (homoean) formula about 357. By the tradition received in the Orthodox Church he repudiated this signature before his death, returning to Córdoba where he reposed soon after.
