The Advance of the Mongols: 6 Campaigns That Built the World's Largest Land Empire

A depiction of the Mongol siege of Baghdad.

The Razing of Baghdad

In 1258, with the Assassins dispatched, Hulegu turned his attention towards his main objective: Baghdad and the Abbasid Caliph Al-Musta’sim. As word of the demise of the Assassins spread local warlords prostrated themselves before Hulegu and offered him their soldiers, doubling the size of the Mongol force. Newly reinforced, Hulegu sent a messenger to Al-Musta’sim demanding that he surrender. The Caliph was persuaded by his chief minister, Al-Alkami, to refuse Hulegu’s demand. What he did not know was that Al-Alkami, was intentionally misleading him. Al-Alkami had been spying for the Mongols and expected that if Baghdad were to fall he might benefit personally.

Al-Musta’sim remained confident, not realizing that he would actually have to defend the city until the Mongols drew to within a day’s ride of Baghdad. He called on the city’s garrison of 20,000 men to ride out and challenge Hulegu, but when the garrison encamped near the Tigris River the Mongols pulled down nearby dykes and dams on the river and flooded the garrison’s camp. Those who did not drown were ridden down by the Mongol’s heavy cavalry.

While the core of Baghdad’s defense already eliminated, Hulegu’s forces went to work on the city itself. The surrounded the city, digging a trench and building a palisade to prevent any of the inhabitants from escaping. Then the bombardment began. Because the Mongols had reached the city faster than they expected the carts carrying the ammunition for the catapults, in disrepair after being dragged up and down the mountains to fight the Assassins, had not yet arrived. They improvised by launching stumps of palm trees and the foundations of buildings into Baghdad.  This rain of odds and end continued for a week before the Mongols finally stormed the ninety foot high eastern wall.

When the Mongols breached the walls Al-Musta’sim attempted to open negotiations with Hulegu, but it was too late. The city surrendered, and the Mongols led what remained of the Baghdad garrison out and executed them one by one. The Caliph exited the city last. After a few taunts from Hulegu was rolled up in a rug and trampled to death by horses, an execution method that complied with the Mongol belief that no man can kill a king and that no royal blood should touch the ground.

Following the death of the Caliph the Mongols moved in to sack Baghdad. The population, which estimates put at 800,000 to 2,000,000 people, was massacred. A few Christians and Jews with connections to Hulegu’s allies were spared, and some of the women and children were kept as slaves, but the rest would die. The city burned, and the Tigris ran black with the ink of the books cast into it from the “House of Wisdom,” the product of four hundred years of work collecting and translating all the knowledge of the known world.  Baghdad would never full recover.