For more than one thousand years, people from every corner of the Greco-Roman world sought the hope for a blessed afterlife through initiation into the Mysteries of Demeter and Kore at Eleusis. In antiquity itself and in our memory of antiquity, the Eleusinian Mysteries stand out as the oldest and most venerable mystery cult. Despite the tremendous popularity of the Eleusinian Mysteries, their origins are unknown. Because they are lost in an era without written records, they can only be reconstructed with the help of archaeology. This book provides a much-needed synthesis of the archaeology of Eleusis during the Bronze Age and reconstructs the formation and early development of the Eleusinian Mysteries. The discussion of the origins of the Eleusinian Mysteries is complemented with discussions of the theology of Demeter and an update on the state of research in the archaeology of Eleusis from the Bronze Age to the end of antiquity.