Despite a marked increase in studies of medieval prostitution in the past thirty years, no study of prostitution in Paris, or of prostitution in the twelfth and thirteenth centuries, has so far been made. This is a particularly striking oversight given that Paris saw the earliest appearance of theological discourses advocating prostitutes' reform, as well as reform houses used for that very purpose; twin developments which shaped the municipal, royal and ecclesiastical policies on prostitution throughout Europe in the fourteenth and fifteenth centuries, and beyond. This book is the first history of Parisian prostitution in the middle ages, and focuses on a crucial turning point in the history of the welfare and the regulation of prostitutes. Part One establishes the social, intellectual and economic context of Paris in this period and examines the complex question of the definition and identity of a prostitute from the late antique through to the twelfth and thirteenth centuries. The place of prostitutes in Parisian society is then explored, and prevailing views of the prostitute as a marginalized character are challenged. Part Two focuses on three key changes in the ecclesiastical response to prostitution that were promoted by Parisian secular clerics: the acceptance of a prostitute's right to earn under certain moral conditions; the inclusion of prostitutes within established systems of penance the setting up of reform houses; and the increasing support for a prostitute's marriage and the changing views of her sexuality. Although never free from the prejudices against her occupation, the prostitute did during this period begin to illicit some sympathy for the woman who existed beneath the traditional stereotypes of sin, sex and greed. This book is not just a history of prostitution, therefore, but a study of social relations between marginal groups and elites, of charity, and of female poverty during a period of great social change.