Justin II
Gregory began as a monk in the monastery of the Byzantines in Jerusalem, or so we learn from Evagrius Scholasticus. He was transferred by the emperor Justin II (565-578 ) to Sinai. He was abbot there when the monastery was attacked by Arabs. John Moschus mentions he was also abbot of Pharan in Palestine. In 569-70 he became Patriarch of Antioch after Justin II deposed the Patriarch Anastasius I of Antioch.