Aftermath of the Mongol Invasion of Persia

Posted by James DeFalkin on Thursday, November 16, 2023

The Aftermath of the Mongol Invasion of Persia

In the early 13th century, the unified Mongol tribes of central Asia began expanding their empire under the ruthless and brilliant leadership of Genghis Khan. After conquering northern China, the Mongols turned their attention westward towards the Islamic world. In 1219, a Mongol army led by Genghis Khan’s youngest son Tolui invaded the Khwarezmian Empire, which encompassed modern-day Iran, Afghanistan, and central Asia. This marked the beginning of the Mongol conquest of Persia.

The Invasion and Fall of Khwarezm

The Shah of the Khwarezmian Empire at the time was Alauddin Mohammad. When Genghis Khan sent a diplomatic caravan to establish trade relations, Inalchuq, the governor of the Khwarezmian city of Otrar, attacked it, claiming they were spies. Enraged, Genghis Khan assembled a massive invasion force to retaliate.

Mongol warrior

In late 1219, the Mongols easily took the important trade cities of Bukhara and Samarkand. Alauddin desperately attempted to raise an army to stop the Mongols, but could not match their speed and numbers. City after city fell to the Mongols as they pushed south towards Persia. In early 1220, the Mongols captured the Khwarezmian capital of Gurganj after a long siege, massacring the inhabitants. Alauddin had already fled west towards the Caspian Sea. He would die of pleurisy on a small island later that year, leaving his decimated empire to collapse.

The Invasion of Persia

With the Khwarezmian Empire destroyed, the Mongols now turned towards the Persian heartland. Their main target was the Abbasid Caliphate and its capital Baghdad. However, Persia was divided between various petty dynasties after the fall of the Seljuk Empire several decades before.

The most important of these local Persian dynasties was the Khwarezmid Empire in the northeast and the Atabegs of Azerbaijan in the northwest. In 1220, the Atabegs hastily assembled an alliance of Persian and Georgian troops to stop the approaching Mongols. They clashed at the Battle of Calderan in modern-day Armenia. Despite being outnumbered six to one, the Mongols decisively defeated the Persian coalition through superior tactics and discipline.

With Azerbaijan crushed, the Mongols conquered the rest of northern Persia over the next few years. The Khwarezmid Empire fell in 1221 after the Siege of Nishapur. The Atabegs of Fars in southern Persia resisted the longest thanks to their isolated geographical position, but surrendered in 1231 after the Mongols diverted the course of a river to flood their capital.

Siege of Baghdad

By the early 1230s, all of Persia was under Mongol control, except for the Abbasid Caliphate based in Baghdad. In 1257, the Mongol leader Hulagu Khan advanced into Iraq with a massive force. On February 13, 1258, after a twelve-day siege, the city of Baghdad surrendered. The Mongols sacked the city, massacring most of the inhabitants. The Abbasid caliphs had ruled an Islamic empire stretching from North Africa to Persia, but now their dynasty was ended by the relentless Mongol conquest.

Mongol Rule and the Ilkhanate

With their conquest of Persia complete, the Mongols now ruled a diverse empire of Muslims, Christians, Buddhists, and others. Initially, the Mongols allowed a degree of religious freedom and did not force their subjects to convert. However, the early Mongol rulers of Persia were relatively intolerant of Islam compared to other religions. Mosques and shrines were occasionally destroyed or turned into stables. Muslims were required to follow Yassa, the Mongol legal code instead of Sharia law.

The founder of the Ilkhanate, Hulagu Khan, enjoyedcohol and patronized Christians and Buddhists. He was likely influenced by his Christian wife and Buddhist mother. The Muslim historian Rashid-al-Din reported that Hulagu Khan once said “I hate Islam and express my contempt for it. I want the rule of the Mongols to replace Islam.”

However, the Mongols also quickly realized the importance of rebuilding Persia’s economy and infrastructure after their devastating invasions. They repaired irrigation networks, encouraged agriculture, and reopened trade routes such as the famous Silk Road. This led to a revival of commerce and urban life. The Mongol elite adopted many aspects of Persian culture, cuisine, and dress. Intermarriage between Mongols and Persians also gradually became common.

The early Ilkhanate rulers after Hulagu Khan’s death in 1265 were fairly tolerant of Islam again. Ghazan Khan, who reigned from 1295-1304, officially converted to Islam, though some later historians question how genuine his conversion was. Under Ghazan Khan’s rule, the Ilkhanate enjoyed a peak of economic prosperity. However, the Ilkhanate began declining rapidly soon after due to civil wars and invasions by neighboring powers. It fragmented after the death of Abu Sa’id Bahadur Khan in 1335.

Smaller regional dynasties emerged from the remnants of the Ilkhanate, including the Jalayirids, the Sarbadars, the Injuids, and the Muzaffarids, who variously controlled parts of Persia over the next century until the rise of the Timurid Empire.


Cultural Impact

The Mongol invasions and subsequent rule indelibly shaped the course of Persian history over the 13th and 14th centuries. The initial invasions were catastrophically destructive and led to widespread massacres in cities like Merv, Nishapur, and Baghdad. Some historians estimate that millions were killed during the conquest period from 1219-1260.

Cities and agriculture went into decline under the instability of the early Ilkhanate. The Abbasid Caliphate and its influential House of Wisdom center of learning at Baghdad were ended. The Islamic world was fractured into smaller warring kingdoms instead of united under one caliphate.

However, the Mongol rulers also reopened Persia to the outside world. Improved travel along the Silk Road introduced new ideas, technologies, and goods.tolerated all religions, allowing Persian culture to partly synthesize with foreign influences. The Mongols transmitted Chinese innovations like printing, paper money, and gunpowder westward. They brought Persian and Chinese scholars together in an exchange of knowledge. The Persian language also expanded as a common literary medium.

The devastation forced many Muslim scholars and elites to flee from Persia into the Mamluk Sultanate in Egypt and Syria. This helped spread Persian culture into the Arab world, which had previously looked down on Persian culture as foreign.

Within Persia, the initial destruction was followed by a resurgence of Persian art, poetry, and literature by the 14th century as stabilization returned. Persian culture and identity survived the conquest and absorbed some Mongol traditions. The Ilkhanate period left a significant legacy and shaped Persia’s development right up to the modern era. The mingling of Mongol and Persian elements contributed to the vibrant diversity of Persian civilization.


Britannica, The Editors of Encyclopedia. “Khwarezm-Shah Dynasty.” Encyclopedia Britannica, September 23, 2020.

—. “Siege of Baghdad.” Encyclopedia Britannica, March 4, 2021.

Khetran, Muhammad. “An Historical Analysis of the Invasion of Mongols.” NUML International Journal of Business & Management 12, no. 2 (August 25, 2017): 1–12.

Morgan, David. “The Mongols in Iran: A Reappraisal.” Iran 42 (2004): 131–36.

Ratchnevsky, Paul. Genghis Khan: His Life and Legacy. Wiley-Blackwell, 1991.

Soucek, Svat. A History of Inner Asia. Cambridge University Press, 2001.