This study of the presence and nature of the cult of Mithras in Roman Britain is based on literary, epigraphic and architectural evidence. Rossi focuses in particular on archaeological evidence from military forts such as Vindolanda, Housesteads and Carnarvon and from London, exploring how the relationship between Mithraism and the military may account for many of the features of its cult in Britain. She concludes that the situation in Britain was different to many other provinces, especially in architectural terms, and that native religious elements limited the expansion of Mithraism, a cult which eventually lost out to Christianity. Includes a large, detailed catalogue of finds. Italian text.