The Life of St Martin by Sulpicius Severus was one of the formative works of Latin hagiography. Yet although written by a contemporary who knew Martin it attracted immediate criticism. Why? This study seeks an explanation by placing Sulpicius works both in their intellectual context and in the context of a church that was then undergoing radical transformation. It is thus both a study of Sulpicius Martin and their world and at the same time an essay in the interpretation of hagiography.