The
Siege of Baghdad, which lasted from January 29 until February 10, 1258, entailed the
investment, capture, and sack of
Baghdad, the capital of the
Abbasid Caliphate, by
Ilkhanate Mongol forces and allied troops. The Mongols were under the command of
Hulagu Khan, brother of the
khagan Möngke Khan, who had intended to further extend his rule into
Mesopotamia but not to directly overthrow the Caliphate. Möngke, however, had instructed Hulagu to attack Baghdad if the Caliph
Al-Musta'sim refused Mongol demands for his continued submission to the khagan and the payment of tribute in the form of military support for Mongol forces in
Iran.