Saint Hosius the Confessor was bishop for more than sixty years in the city of Cordova (Spain) during the fourth century. The holy emperor St Constantine the Great (306-337) deeply revered him and made him a privy counsellor. The saint advised St Constantine to convene the First Ecumenical Council at Nicea in 325, and he was the first to sign the acts of this Council.

After the death of St Constantine the Great, St Hosius defended St Athanasius of Alexandria (May 2) against the emperor Constantius (337-361), an advocate of the Arian heresy. Because of this, they sent him to prison in Sirmium.

St Hosius died in the year 359 after his return to Cordova.