Leo I the Thracian
Cybistra was from an early stage a Christian bishopric, as shown by the participation of its bishop Timotheus in the First Council of Nicaea in 325. Cyrus took part in the Council of Chalcedon in 351 and was a signatory of the letter that the bishops of the Roman province of Cappadocia Secunda, to which Cybistra belonged, sent in 458 to Byzantine Emperor Leo I the Thracian after the murder of Proterius of Alexandria. The diocese no longer appears in "Notitiae Episcopatuum" from the end of the 15th century.