The last forty years have brought about a transformation in the understanding of pagan Roman religion, rescuing it from the margins of the discipline and restoring its rituals and rhythms to their place at the centre of Roman life and literature. This book provides an up-to-date account of the religious history of Rome starting from its mythical origins, describing its character and development through the later Republican centuries and assessing the response of pagans to the coming of new religious forms during the centuries of Roman imperial rule. It places great emphasis on the fundamental difference between modern ideas of what a religion ought to be and the realities of ancient life. The book is designed to be accessible to all those approaching the subject for the first time, whether their interest is in the classical world or in comparing its religious forms with those of other times and places.