The Roman festival of the Lupercalia is one of the most discussed issues in the field of pre-Christian Roman religion. Hardly a year goes by without an article on the subject appearing in a major Classics journal. But the festival presents a range of issues that individual articles cannot address. This thesis is an attempt to present a modern analysis of the phenomenon of the Lupercalia as a whole, including literary, archaeological and historical evidence on the subject. The first section presents the ancient sources on the Lupercalia, and is divided into five chapters, each analysing a particular aspect of the festival: fertility, purification, the importance of the wolf and the foundation myth, the mythology of Arcadian origins, and Caesar's involvement with the Lupercalia of 44 BC. The second section places the Lupercalia in a wider context, discussing the festival's topography and the course of the running Luperci, its relationship to other lustration rituals, and its position in the Roman calendar, ending with an appraisal of the changes it underwent in late Antiquity. The third section employs methods from linguistics, anthropology and comparative religion to show that the Lupercalia involved a ritual of initiation, which was also reflected in the Roman foundation myth. The central chapter of this section discusses the methodology used in comparative Indo-European mythology, and offers a case study that parallels the god of the festival (Faunus) with Rudra of Vedic Hinduism. The last chapter considers other parallels with Indian religion, especially the relationship between flamen and brahmin. The thesis challenges a number of established theories on the subject and offers new evidence to show that the festival has Indo-European origins, but also that it played an important role throughout Roman history.