Jane Ellen Harrison transformed the study of Greek religion with her discovery of a religious system predating that of the Olympic gods and goddesses familiar to the modern world. This book introduces her work and ideas, which have influenced and profoundly shaped scholarship, primarily in the classics, throughout the last century. Through her penetrating study of Greek art and epigraphy, she found evidence of rituals of this religion that had been hiding in plain sight for centuries. This earlier religion had a darker, chthonic character in which goddesses, underworld divinities, and daemons played a much larger role.