Siege of Baghdad (1401)
In 1401, Timur besieged Baghdad for forty days and then massacred its inhabitants for resisting. The Mongol army looted the treasury and razed much of the city, except for mosques and madrasas. Contemporaries reported that each Mongol soldier was ordered to bring at least one severed head of an inhabitant. Only one out of a hundred of the city's inhabitants reportedly survived the massacre to be sold into slavery.