This collection of papers, many of them either published here in English for the first time or previously available only in specialist libraries, deals with the religious history of the Roman Empire. Written by leading scholars, the essays have contributed to a revolutionary change in our understanding of the religious situation of the time, and illuminate both the world religions of Christianity and Judaism and the religious life of the pagan Empire in which these developed and which deeply influenced their characters. No knowledge of ancient languages is presupposed, so the book is accessible to all who are interested in the history of this crucial period.