The Roman foundation myth has been the subject of classical scholarship for centuries. But much in the story of Romulus and Remus remains unexplained. This is the first English language book-length study of the Lupercalia, a religious festival central to understanding both the Roman foundation myth and the history of Rome. The festival of the Lupercalia was a male initiation ritual and shares a number of traits with similar rituals across the world. The agonistic elements in the story of Romulus and Remus and the Lupercalia can be compared to a number of Vedic rituals and traced back to a common Indo-European prehistory. The Lupercalia celebration remained a central annual event throughout the history of Rome and reflected political and social life in the city. Caesar used it to stage a refusal of kingship and Augustus restored its initiatory aspect, which continued in the period of the Empire. It survived all attempts of Christian prohibition to appear in the form of a carnival that criticized the pope in the late 5th century. In sum, the book offers a new interpretation of the Roman foundation myth and the Lupercalia. It follows the transformation of a unique ritual from its Indo-European roots through Roman history to late antiquity.