The Mongols Sack Baghdad and End the Abbasid Caliphate
Hulagu Khan's siege destroys the House of Wisdom and closes the Golden Age
Quick facts
- Mongol commander
- Hulagu Khan
- Siege dates
- January-February 1258 CE
- Caliph executed
- Al-Musta'sim, the last Abbasid caliph in Baghdad
- Institution destroyed
- The House of Wisdom
What happened
By the 1250s the Abbasid Caliphate, weakened by centuries of fragmenting political authority to regional dynasties and to the Seljuk and other Turkish sultans who had come to dominate its military affairs, still held Baghdad as a religious and symbolic center. The Mongol prince Hulagu Khan, grandson of Genghis Khan, was tasked with subduing western Asia, and after crushing the Nizari Ismaili state in 1256 CE he moved against the Abbasid Caliphate in Iraq, defeating it in January 1258 CE. Mongol forces captured Baghdad the following month after a brief siege, and a week-long slaughter followed, killing up to 800,000 people according to tradition, along with the execution of the last Abbasid caliph, al-Musta'sim. The Mongols destroyed the city's mosques, palaces, hospitals, and libraries, including the House of Wisdom, whose books were reportedly thrown into the Tigris River in such numbers that the water ran black with ink.
Why it matters
The sack of Baghdad ended the Abbasid Caliphate's five centuries of rule from the city and is widely treated by historians as the symbolic close of the Islamic Golden Age's Baghdad-centered phase, even though scholarship and trade continued elsewhere in the Islamic world, including in Cairo under the later Mamluk Sultanate. The destruction pushed the Mongols to the edge of Mamluk territory, setting up their defeat two years later at Ain Jalut, the first major check on Mongol expansion.
How we know
The siege's timeline and the scale of destruction are documented in the World History Encyclopedia's articles on the Ilkhanate and the Abbasid Dynasty; the 800,000 casualty figure is explicitly presented in that scholarship as a traditional estimate rather than a verified count.
Sources
- World History Encyclopedia. Ilkhanate · Reputable sourceworldhistory.org · The domain "worldhistory.org" is on our Reputable source registry. · Link is live and its text matches the event's key terms (Jul 2026)
- World History Encyclopedia. Abbasid Dynasty · Reputable sourceworldhistory.org · The domain "worldhistory.org" is on our Reputable source registry. · Link is live and its text matches the event's key terms (Jul 2026)
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Related timelines
- The Mongol Empire → · See the full campaign of Hulagu Khan and the wider Mongol conquests on the Mongol Empire timeline