Original: The Battle of Baghdad in 1258 was a key event in world history in which the Mongols under Hulagu Khan , a grandson of Genghis Khan , destroyed Baghdad , the capital of the Abbasid Caliphate and at the time the greatest center of Muslim power .
Simplified: The Battle of Baghdad in 1258 was a victory for the Mongol leader Hulagu Khan , a grandson of Genghis Khan .