Situated in a period that witnessed the genesis of institutions fundamental to this day, this path-breaking study offers a comprehensive look at how ancient Christian women initiated ascetic ways of living, and how these practices were then institutionalized. Using the organization of female asceticism in Asia Minor and Egypt as a lever, the author demonstrates that - in direct contrast to later conceptions - asceticism began primarly as an urban movement. Crucially, it also originated with men and women living together, varying the model of the family. The book then traces how, in the course of the fourth century, these early organizational forms underwent a transformation. Concurrent with the doctrinal struggles to redefine the Trinity, and with the formation of a new Christian élite, men such as Basil of Caesarea changed the institutional configuration of ascetic life in common: they emphasized the segregation of the sexes, and the supremacy of the rural over urban models. At the same time, ascetics became clerics, who increasingly used female saints as symbols for the role of the new ecclesiastical elite. Earlier, more varied models of ascetic life were either silenced or condemned as heretical; and those who had been in fact their reformers became known as the founding fathers of monasticism.