Before the Mongols came, Herat was one of the great cities of the medieval Islamic world. Its markets hummed with the trade of textiles and goods moving along routes connecting Persia to Central Asia. Skilled artisans worked in its workshops. Scholars studied in its madrasas. The city belonged to the Khwarazmian Empire, and its defenses followed the classic Central Asian pattern: a citadel on high ground, a walled inner city where most people lived, and suburbs sprawling beyond the fortifications. The governor, Malik Shams al-Din Muhammad Juzjani, commanded what chroniclers estimated at 100,000 to 190,000 defenders. These numbers are almost certainly exaggerated, but they suggest a garrison of considerable strength. Herat was not a city that expected to fall easily.

Tolui arrived in late May or early June 1221, fresh from destroying Nishapur. His forces approached from the north, through Baghis, after sacking the citadels of Fushanj and Kusui along the way. For seven days and nights, the fighting was savage. The chronicler Herawi recorded that over 30,000 men on both sides died on the first day alone, including 1,700 Mongol nobles. During the desperate struggle, Herat's governor was killed, and his death broke his soldiers' morale. On the eighth day, a hundred nobles and merchants, led by Ezz al-Din Moqaddam Heravi, walked out of the city carrying nine fine linen tunics as gifts. They came to negotiate. By the tenth day, it was over. The Mongols stormed the Sikandar district and massacred nearly a quarter of its population. They installed two governors and a garrison, then Tolui departed to rejoin his father at Taloqan.

For a few months, Herat existed under Mongol occupation. Then, in November 1221, news reached the city that the Mongols had been defeated at the Battle of Parwan. The people of Herat rose up. They lynched the governor Abu Bakr near the citadel. Angry mobs swept through the streets, killing every Mongol soldier they could find. One account claims agents from the fortress of Kalyun had infiltrated the city months earlier, disguised as merchants with weapons hidden in their clothing, orchestrating the revolt from within. Genghis Khan's response was absolute. He ordered that the inhabitants of Herat be shown no mercy. The general Eljigidei arrived with 60,000 to 80,000 troops, possibly reinforced by another 50,000 from the Amu Darya. The second siege lasted seven months, a testament to the city's defenses remaining largely intact from the first, negotiated surrender. The Mongols suffered nearly 5,000 casualties before 400 soldiers finally breached the walls. Fighting inside the city raged for three more days.

The chronicler Celebi estimated 300,000 lives lost in the second siege. Medieval numbers are notoriously unreliable, but even the most conservative accounts describe catastrophic destruction. One story survived across the centuries: an old man, emerging from the ruins, looked at what remained of the city and simply thanked God that it was all over. The devastation was so complete that when Khagan Ogedei ordered Herat's reconstruction in 1236 -- fifteen years later -- his first priority was repairing a canal so wheat could grow again. There were no farmers left. There was no livestock. The pearl of Khorasan had been reduced to rubble and silence. That Herat would eventually rebuild, becoming once more a center of learning and art under the Timurids, speaks to the resilience of the place and its people. But the scars of 1221 cut deep into the city's memory, a reminder of how quickly centuries of civilization can be unmade.