Moses was repeatedly imprisoned for refusing to pay new taxes imposed on ecclesiastical landholdings. During the revolt against Umayyad rule (747–750), Moses (by now an old man) and Michael were both summoned before the Umayyad caliph Marwan II. According to John the Deacon, Moses was severely beaten, yet gave thanks to God that he was found worthy to suffer for the church. John, who wrote the second section of the "History of the Patriarchs of Alexandria", was a spiritual disciple of Moses.