Gregory of Nyssa, Saint, d. 394?, Cappadocian theologian; brother of St. Basil the Great and his successor as champion of orthodoxy. He became bishop of Nyssa in Cappadocia in 371, was removed in 376, and was restored in 378. He was prominent in the First Council of Constantinople (see Constantinople, First Council of). His fame rests on his theological works, most of which were controversial, against Eunomius, Apollinarians, and against the teachings of Jews and pagans (Oratio catechetica). Feast: Mar. 9.