A wide range of physical activities is recognized to take place during sleep, including not only common behaviors such as sleepwalking and sleeptalking, but also violent activities that may lead to injury to the sleeper, the bed partner, or another person nearby. Any data regarding the details of what occurs during these violent episodes come only from individual case reports and short series. This article examines the historical literature to characterize the features of sleep violence more precisely, and to relate these events to the modern understanding of the underlying neurologic abnormalities during non–rapid eye movement sleep arousal disorders.