The Sack of Baghdad — the Mongols storm the Abbasid capital in 1258

In February 1258, the Mongol army of Hulagu Khan — a grandson of Genghis Khan — stormed Baghdad, the capital of the Abbasid Caliphate, and extinguished a dynasty that had claimed the leadership of the Sunni Muslim world for five centuries. The Mongols invested the city on or about 29 January, breached its walls within days, and accepted the surrender of the caliph al-Musta’sim on 10 February. The sack that followed killed an immense number of the city’s inhabitants, scattered or burned its great libraries, and left Baghdad a depopulated ruin. The caliph himself, the thirty-seventh and last of the Abbasid line, was executed on 20 February — rolled in a carpet and trampled to death by horses, by an account widely repeated, so that no royal blood would touch the ground.

The dynasty that ended had been founded in 750, when the Abbasids overthrew the Umayyads, and from its purpose-built capital at Baghdad, established in 762, it had presided over the most brilliant period of medieval Islamic civilization. By the thirteenth century, however, the caliphate’s real power had long drained away. For three hundred years the caliphs had reigned more than they ruled, their authority eclipsed first by Persian and then by Turkish military dynasties — the Buyids and the Seljuks — who held the caliph as a revered figurehead. What Hulagu conquered was a city and a symbol, not the empire of Harun al-Rashid.

The mechanism of the fall combined a vast, methodical war machine with a defender who had neither the force to resist it nor the realism to submit in time. Hulagu had been dispatched from Mongolia with an enormous army and explicit orders to subdue the Islamic heartland. Al-Musta’sim, by contrast, presided over a divided and reduced court, dismissed the danger, refused the Mongols’ demands, and failed to mobilize, even as his armies were destroyed outside the walls. His misjudgment did not cause the disparity of power, but it ensured that the disparity ended in massacre rather than negotiated surrender.

The consequences outlasted the rubble. The killing of the caliph left Sunni Islam without the office that had symbolically united it since the death of the Prophet, and the political shock of an Islamic capital destroyed by non-Muslim conquerors reverberated for generations. The destruction of Baghdad’s books and scholarship became, in later memory, the emblem of a lost golden age — though the city’s intellectual life was not annihilated as totally as legend holds, and libraries reopened within a few years. What was beyond dispute was that an institution more than five centuries old, and the city that had been the center of a world, were broken in a single fortnight.

The Mongol Conquest of Khwarazmia — a rich empire annihilated city by city

Between 1219 and 1221, the Khwarazmian Empire of Central Asia — one of the wealthiest states of the Islamic world, spanning much of present-day Iran, Afghanistan, and the lands between the Caspian and the Pamirs — was destroyed by the Mongol armies of Genghis Khan. Its great cities of Bukhara, Samarkand, Gurganj, Merv, and Nishapur were stormed in succession and, in several cases, depopulated; their inhabitants were slaughtered or enslaved in numbers the medieval chroniclers counted in the hundreds of thousands. The empire’s ruler, Shah Ala ad-Din Muhammad II, fled westward and died in destitution on an island in the Caspian Sea around the end of 1220, his realm dissolving behind him.

The campaign is remembered above all for its violence. Where cities resisted or revolted, the Mongols razed them and put the population to the sword; the chroniclers Juvayni and Ibn al-Athir record death tolls at Merv and Nishapur running into the high hundreds of thousands, and while such figures are inflated and debated, the scale of the killing was extraordinary by any measure. A prosperous, irrigated region of millions was reduced, within two years, to a depopulated ruin from which parts of it never recovered. The dead were farmers, weavers, scholars, and townspeople of Khorasan and Transoxiana, and the record of their destruction belongs to them.

The trigger was a diplomatic atrocity. In 1218 the governor of the frontier city of Otrar seized a large Mongol trade caravan, accused its members of spying, and had them killed; when Genghis Khan sent envoys to demand redress, the Shah had one executed and the others humiliated. For a ruler who treated the safety of envoys and merchants as inviolable, this was a casus belli, and the Mongols answered it with annihilation. A quarrel that might have been settled by the surrender of one governor became the destruction of an empire.

Yet the deeper cause lay in the Khwarazmian state itself. It was a recent, overextended creation, its army large but its loyalties fragile, its provinces newly conquered and resentful, and its Shah distrustful of his own commanders. Faced with a faster, better-coordinated enemy, Muhammad II chose to scatter his forces among the cities rather than meet the Mongols in the field — a decision that let them be destroyed one garrison at a time. The empire fell not only because the Mongols were ruthless and disciplined, but because it was brittle, divided, and badly led at the moment of the shock.