There have been important mediums and researchers throughout the history of psychical research in many parts of the world, but the period from the 1880s to the 1930s saw a coming together of outstanding scientific minds in Europe and the USA who probed the phenomena of mental mediumship with a diligence, intellectual discipline and degree of enthusiasm not encountered on such a scale before or since. This period saw the establishment of the Society for Psychical Research in Britain (1882), followed swiftly by the American Society for Psychical Research (1884), which resulted in close collaboration between people who, apart from their intellects, also had the financial means and the time to devote to the subject. In this book Alan Gauld, whose works on mediumship, psychical research and psychic phenomena have become classics in the genre, offers important insights into aspects of the early days of mediumship research that over the years have largely gone off the radar. Here we see the great names of psychical research as real people in personal relationships, and we learn about the informal beginnings of serious investigations and explore their cultural context. The Heyday of Mental Mediumship is destined to become Gauld's magnum opus.