The bishop of Niš in 343. He attended the Council in Serdica (Sofia) held in 343. At the Council he was sticking to the symbols of creed, established at the First Ecumenical Council of Nicaea in 325, and he was an advocate of the Orthodox confession of faith. The church canons established at the Serdica Council were forwarded to the Pope Julius I, and they bear his name - Gaudentius ab Ahaia de Naisso. After the Council, St. Athanasius the Great spent the Easter time of 344 together with Gaudentius in Niš. Most probably, he remained in Niš until 350, when the Emperor Constans I, the ruler of the Empire western part and protector of Orthodoxy and its bishops, passed away.