This is the first book to provide a comprehensive account of the emergence of monasticism from its roots in late antiquity and its transition to the early medieval West. Beginning with the search for individual perfection in the context of the religious and social climate of fourth-century Egypt, it traces the adoption and transformation of monastic ideas and practices first by the elites of the western Roman Empire and later by the royalty and aristocracy of the so-called 'barbarian' kingdoms, including the Franks and Anglo-Saxons. It tracks the development of monastic rules and includes sections on female asceticism and monasticism, on Irish monasticism and its influence, and the developing theology of afterlife and intercession. This unique work is based on a detailed consideration of the texts, their use and adaptation, and is the first treatment of the subject to draw together social and religious approaches. The book offers a number of original perspectives on major issues and controversies.