We tend to think of sleep as a private concern, a night-time retreat from the physical world into the realm of the subconscious. Yet sleep also has a public side; it has been the focal point of religious ritual, philosophic speculation, political debate, psychological research, and more recently, neuroscientific investigation and medical practice. In this first ever history of sleep research, Kenton Kroker draws on a wide range of material to present the story of how an investigative field – at one time dominated by the study of dreams – slowly morphed into a laboratory-based discipline. The result of this transformation, Kroker argues, has changed the very meaning of sleep from its earlier conception to an issue for public health and biomedical intervention. Examining a vast historical period of 2500 years, Kroker separates the problems associated with the history of dreaming from those associated with sleep itself and charts sleep-related diseases such as narcolepsy, insomnia, and sleep apnea. He describes the discovery of rapid eye movement – REM – during the 1950s, and shows how this discovery initiated the creation of 'dream laboratories' that later emerged as centres for sleep research during the 1960s and 1970s. Kroker's work is unique in subject and scope and will be enormously useful for both sleep researchers, medical historians, and anybody who's ever lost a night's sleep.