This literature review examines the history of Dissociation Identity Disorder (DID) previously referred to as Multiple Personality Disorder (MPD). This book deals with literature from ancient Egyptian times through 1994 when the American Psychological Association (APA) officially changed the term from MPD to DID to the present. This historical review of this mental coping mechanism in the face of trauma begins with the ancient Egyptians, when some gods were composed of the essence of multiple creatures to form one god. These ancient cultures set a foundation that western culture used to assist in the creation of the field of psychology. This story continues into the late eighteen hundreds as Freud, Charcot, Janet, and others, not only diagnose a condition of hysteria, but initiate treatment. This review continues through the combat trauma of war in the twentieth century in which post-traumatic stress was found to lead to DID. From the nineteen-fifties to the nineteen-nineties, several well-publicized cases of MPD are reviewed, and the final result is one document that provides therapists and lay-persons alike with the history of dissociation and MPD that assists in their understanding of the condition.