Conrad Leyser examines the formation of the Christian ascetic tradition in the western Roman Empire during the period of the barbarian invasions, c.400-600. In an aggressively competitive political context, one of the most articulate claims to power was made, paradoxically, by men who had renounced 'the world', committing themselves to a life of spiritual discipline in the hope of gaining entry to an otherworldly kingdom. Often dismissed as mere fanaticism or open hypocrisy, the language of ascetic authority, Conrad Leyser shows, was both carefully honed and well understood in the late Roman and early medieval Mediterranean. Dr Leyser charts the development of this new moral rhetoric by abbots, teachers, and bishops from the time of Augustine of Hippo to that of St Benedict and Gregory the Great.