The Mongols Devastate Persia
A murdered diplomatic mission triggers the destruction of Persia's greatest cities
Quick facts
- First invasion
- 1218-1220 CE, under Genghis Khan
- Cities destroyed
- Bukhara, Samarkand, Herat, Nishapur, Merv
- Second invasion / Ilkhanate founded
- 1253-1260 CE, under Hulagu
- Ilkhanate rulers' later religion
- Adopted Islam
What happened
Genghis Khan sent a diplomatic mission demanding the Shah of the Khwarazmian Empire, which then ruled Persia and Central Asia, submit to Mongol overlordship. The Shah had the ambassadors executed, and Genghis responded by fielding an army of roughly 100,000 men that swept through Persia between 1218 and 1220, forcing the Shah to flee to an island in the Caspian Sea. Mongol forces captured and destroyed Bukhara and Samarkand, then swept through Khorasan, massacring the inhabitants of Herat, Nishapur, and Merv, three of the largest cities in the medieval world, and wrecking the region's irrigation systems along with them. A second wave under Hulagu invaded Persia and the wider Middle East between 1253 and 1260, establishing the Ilkhanate, a Mongol-ruled khanate that governed Iran for decades before its rulers gradually adopted Islam themselves.
Why it matters
The Mongol invasions killed enormous numbers of people and destroyed infrastructure, libraries, and centers of learning across Persia on a scale that took generations to recover from. Yet the eventual Islamization of the Ilkhanate's Mongol rulers repeated a pattern already visible after the Arab conquest: conquerors of Persia tended, over time, to be absorbed into Persian and Islamic civilization rather than simply replacing it.
How we know
The Mongol campaigns in Persia are documented in Persian chronicles written in the following century, including accounts by officials who served under Mongol rule, and corroborated by the Mongols' own recorded administrative and military records.
Sources
- World History Encyclopedia. Genghis Khan · 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. Mongol Empire · 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)
See something wrong? . Corrections with a source get fixed fastest.
Related timelines
- The Silk Road → · The Mongol conquests that devastated Persia also reopened long-distance Silk Road trade under the later Pax Mongolica; see the Silk Road timeline.