It is well known that Christian hagiography, as a literary genre, has a checkered history; over the centuries it has served many purposes, well beyond the simple one of recounting the facts of the life and exploits of saints and martyrs. 1 Sometimes its principal purpose has been to commend a certain profile of the virtuous life, or the maintenance of doctrinal purity, or to lay a claim to orthodoxy on the part of a particular enclave within the community, even to legitimate the claims of some political regime. In some works these overriding purposes have all but eclipsed the profile of the person whose story they purport to tell. Indeed, in some cases, as in the Life of Theodore of Edessa, the saint himself seems almost to have been invented for the sake of the ulterior motives of the hagiographer, so dim has the portrait of the holy man become behind a cloud of other concerns. The real heroes of the piece are the monastery of Mar Saba, the see of Jerusalem, with its holy places, and the desert monks, who are presented as the guarantors of Christian orthodoxy in the Islamic milieu.