John of Damascus

John of Damascus (c. 675–749) was a Christian monk, priest and theologian born in Damascus under the Umayyad caliphate, where his family had served the Muslim rulers as financial officials. He later withdrew to the monastery of Mar Saba near Jerusalem. When the Byzantine emperors launched their campaign against icons, he wrote three treatises defending the veneration of holy images, which became the classic statement of the Orthodox position. His Fount of Knowledge offered a systematic summary of Christian doctrine, and his hymns are still sung in Eastern churches. He is honored as a saint and Doctor of the Church.