Mongols had repeatedly crushed spread of Islam or corrupted their history Specially in the regime of Halagu Khan. During 13th Century it Happened.
- The Mongols looted and then destroyed mosques, palaces, libraries, and hospitals. Grand buildings that had been the work of generations were burned to the ground.
- The caliph Al-Musta'sim was captured and forced to watch as his citizens were murdered and his treasury plundered. According to most accounts, the caliph was killed by trampling. The Mongols rolled the caliph up in a rug, and rode their horses over him, as they believed that the earth would be offended if it were touched by royal blood.
- Citizens attempted to flee, but were intercepted by Mongol soldiers who killed in abundance, sparing neither women nor children. Martin Sicker writes that close to 90,000 people may have died. Other estimates go much higher. Wassaf claims the loss of life was several hundred thousand. Ian Frazier of The New Yorker says estimates of the death toll have ranged from 200,000 to a million.
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Baghdad had for centuries been the capital of the Abbasid caliphate, the third caliphate whose rulers were descendants of Abbas, an uncle of Muhammad.