This book presents the first ever critical edition and complete translation of the Syriac Life of Saint Simeon of the Olives, who was an abbot of Qartmin Monastery in Tur Abdin and a bishop of the city of Harran in the late seventh and early eighth century AD. His career coincided with the beginnings of the incorporation of North Mesopotamia into the expanding Muslim Empire, and offers fascinating insights into this process and the role that SImeon himself played in it, particularly his interaction with Muslim authorities in the cities of Nisibis and Harran. The Life is analyzed from historical and literary perspectives, and its material context is explored by recourse to the latest archaeological surveys and excavations in the region where Simeon lived and worked. The book also follows Simeon as he was transformed into a champion of West Syrian Christianity by later members of that community, who portrayed him as engaging in amicable debates with the intellectually curious caliph al-Ma'mun (813-33) and leading Muslim theologians at his court.