The Dionysian Mysteries were a ritual of ancient Greece and Rome which used intoxicants and other trance-inducing techniques (like dance and music) to remove inhibitions and social constraints, liberating the individual to return to a natural state. It also provided some liberation for those marginalized by Greek society: women, slaves and foreigners. In their final phase the Mysteries shifted their emphasis from a chthonic, underworld orientation to a transcendental, mystical one, with Dionysus changing his nature accordingly. By its nature as a mystery religion reserved for the initiated, many aspects of the Dionysian cult remain unknown and were lost with the decline of Greco-Roman polytheism; our knowledge is derived from descriptions, imagery and cross-cultural studies.