My project is the completion of a book-length history of the origins of the requirement of sexual continence for bishops, presbyters, and deacons in the Western Christian church. It will also examine the emergence of a parallel requirement of celibacy for bishops in Eastern Christianity. Sexual continence in marriage has served as a distinctive mark of the higher clergy from the fourth century onward, but the precise reasons for the requirement remain poorly understood. My book aims to clarify both the chronology of this development and the reasons for it. It will thus shed light on an important institution in Western culture and be of value to historians, theologians, scholars of religion, and those interested in the role of religion in society.