In this groundbreaking work, David Ulansey challenges the view that the ancient Roman mystery religion of Mithraism derived from an ancient Iranian cult, instead offering a radically different theory of its origins. Arguing that it began as a religious response to the startling discovery of the equinoxes, he shows that Mithraists believed this scientific finding revealed the existence of a new god who possessed the power to shift the structure of the entire universe. The knowledge of this cosmic deity's powers constituted the central secret of Mithraism, and its arcane iconography a sophisticated astronomical code. Brimming with the excitement of a detective story, Ulansey's compelling volume presents a surprising new explanation of one of the most unusual religious phenomena of antiquity.In the centuries following the conquests of Alexander the Great the dramatic unification of the Mediterranean world created exceptionally fertile soil for the growth of new religions. Christianity, for example, was one of the innovative religious movements that arose during this time. However, Christianity had many competitors, and one of the most remarkable of these was the ancient Roman mystery religion of Mithraism.Like the other mystery cults of antiquity, Mithraism kept its beliefs strictly secret, revealing them only to initiates. As a result, the cult's teachings were never written down. However, the Mithraists filled their temples with an enigmatic iconography, an abundance of which has been unearthed by archaeologists. Until now, all attempts to decipher this iconography have proven fruitless. Most experts have been content with a vague hypothesis that the iconography somehow derived from ancient Iranian religion.In this groundbreaking work, David Ulansey offers a radically different theory. He argues that Mithraic iconography was actually anastronomical code, and that the cult began as a religious response to a startling scientific discovery. As his investilU