Killing a sleeping person is a popular motif in world literature and can be found already in the Iliad, with the murder of the sleeping Rhesus. The present paper surveys the motif of killing a sleeper in Greek and Roman literature and in iconography, where the dastardliness of the deed is clearly accentuated. The sleeping chamber was hard for outsiders to access, for which reason this method of killing was prioritised by certain groups, such as slaves and women. In the (...) same way, both these groups acted as accomplices by allowing the murderer access to the bedroom. In the military sphere, the nocturnal attack is a topos for the immoral military conduct of barbarians. However, the sudden attack on a sleeping army was used also by the Romans in desperate military situations or as an act of reprisal for strategic purposes. Overall, a moral valuation of this method of violence can be confirmed, based on similar motives. (shrink)