Gregorius (13) I., bp. of Nazianzus in Cappadocia, father of Gregorius Nazianzenus. [See Gregorius (14).] Originally a member of the Hypsistarii, a sect numerous in Cappadocia, he was converted to the Catholic faith, married a lady named Nonna, and was soon afterwards consecrated bp. of Nazianzus, c. 329. He was a pillar of the orthodox party, though weak enough to sign the creed of Ariminum in deference to Constantius, a.d. 360. He took part in the ordination of Basil to the see of Caesarea [See Basilius]; he opposed the attempts of the emperor Valens, a.d. 371, to overthrow the Catholic faith; yet he, as well as Basil, was spared the banishment inflicted on many bishops (Socr. iv. 11). After an episcopate of 45 years, he died a.d. 374. His son frequently mentions his good father, both in his sermons and his verses, and pronounced a funeral oration over him. Greg. Naz. Oratio xviii. in Migne, Patr. Gk. xxxv. 330; Le Quien, Oriens Christ. i. 411.