In the mid-ninth century, the east Syrian bishop Thomas of Margā composed a lenghy monatic history now known as The Book Of Governors. Amidst Thomas’s numerous anecdotes concerning the exploits of Christian holy men, appear over a dozen stories involving Muslim characters. A critical examination of these tales focusing on issues of word choice, characterization, and narrative assumptions provides important data for the development of Christian depictions of Muslims, as well as for the early history of Christian/Muslim relations. Despite their value, modern scholarship has almost completely neglected Syriac monastic histories such as The Book Of Governors. A recognition of how useful these texts can be for medieval history forces us to rethink modern genre distinctions and argues against a sharp delineation between the often used categories of history and hagiography.