John of Damascus and the Systematization of Orthodox Doctrine

John of Damascus (c. 675–749, also known by his Arabic name Mansur ibn Sarjun) was born in Damascus into a prominent Christian family that had long served in the fiscal administration of the Umayyad Caliphate; his grandfather Mansur ibn Sarjun is reported by the historian Theophanes to have negotiated the surrender of Damascus to the Arab conquerors in 635, and John himself is said to have initially followed his father into a comparable administrative post under Caliph Abd al-Malik or his successor before withdrawing, at some point in the early 8th century, to become a monk at the monastery of Mar Saba in the Judean desert near Jerusalem, then under Islamic rule.