Ibora is a titular see in the Roman Catholic ecclesiastical province of Helenopont, suffragan of Amasia. Its site is at Turhal, Tokat Province, Turkey. According to some sources, the primitive name of the city was Gaziura, formerly a royal city, mentioned by Strabo as deserted (XII, xv: Dio Cassius, xxxv, 12). In fact a Greek inscription, which dates from the time of Mithridates VI of Pontus, has been discovered on the rock of the fortress; a subterranean gallery, hewn from the rock, descends to the interior of the mountain and served perhaps as a secret depository for the royal treasures. Evagrius Ponticus, the famous Origenist ascetic of the fourth century, was a native of Ibora (Sozomen, "Hist. Eccl.," VI, xxx); situated not far from it was Arnesi, the property of Saint Basil, who led a religious life on the bank of the river Iris with his friend Saint Gregory and his sister Macrina. There is frequent mention in the correspondence of these two saints of Ibora, which, according to Procopius (Historia Arcana, xviii), was destroyed by an earthquake in the sixth century. Le Quien (Oriens Christ., I, 533) mentions seven bishops of Ibora, from the fourth to the ninth century. The bishopric still existed about the year 1170 under Manuel Comnenus (Hierocles; Parthey, "Hieroclis Synecdemus," 108).