What Was the Mongol Empire?


Posted by James DeFalkin on Thursday, November 30, 2023


The Mongol Empire was the largest contiguous land empire in history. At its peak in the 13th and 14th centuries CE, the Mongol Empire stretched from Eastern Europe to the Sea of Japan, covering large parts of Asia and Eastern Europe and consisting of modern day countries such as China, Mongolia, Korea, and parts of Russia, Kazakhstan, Kyrgyzstan, Uzbekistan, Turkmenistan, Georgia, Armenia, Azerbaijan, Iran, Iraq, Turkey, Bulgaria, Hungary and Poland (“Mongol Empire” 2022). The empire was founded in 1206 CE by Genghis Khan and lasted for about 150 years before it finally fragmented into smaller khanates and entities. This article will explore the rapid expansion of the Mongol Empire under the rule of Genghis Khan and his successors as well as the eventual decline and breaking apart of this vast empire built on conquests.

The Rise of Genghis Khan

The man who would unite the nomadic tribes of northeast Asia into one of the largest empires in human history was born as Temüjin, son of a Mongol chieftain, around 1162 CE near the modern day border between Mongolia and Siberia (“Genghis Khan” 2022). As a child, Temüjin learned the harsh nomadic lifestyle of the steppes as well as skills like riding horses and using weapons. His early life was marked by conflicts and rivalries with other tribes. At age 9, his father was poisoned to death by a rival tribe, leaving his family without protection.

Temüjin began gathering followers who were attracted by his vision to unite the Mongol tribes and end intertribal warfare. Through his military brilliance, political genius and merciless discipline, he united the tribes by 1206 CE and took on the title “Genghis Khan” meaning “universal ruler” (Weatherford, 2010). Genghis Khan instituted major reforms including the imposition of a written script as a means to unify record keeping and codified laws. He also granted religious freedom, promoted trade, and exempted priests, scholars and teachers from taxation (“Genghis Khan Biography” 2022).

Conquests and Expansion Under Genghis Khan

Once the nomadic tribes were successfully united, Genghis Khan could turn his attention outward. Through a series of methodical military campaigns, he expanded Mongol control outward in all directions from the Mongolian steppe. His highly mobile and disciplined cavalry units of tens of thousands of horsemen with superior archery skills overwhelmed opponents that often fought as individual tribes or factions rather than unified nations.

Key conquests under Genghis Khan included:

  • Western Xia kingdom: The Tangut kingdom of Western Xia in northwest China fell to the Mongols in a series of campaigns from 1209-1227 CE, adding former Chinese imperial territory to the empire (May, 2012).

  • Jin dynasty of northern China: The Jurchen-led Jin dynasty controlled northern China until falling to the Mongols in a series of wars starting from 1211 CE. By 1234 the Jin had been completely conquered in northern China including taking their capital Kaifeng and territory as far south as the Yellow River (“Jin dynasty” 2022).

  • Khwarazmian Empire: The Turkish-led Sunni empire based in Persia controlled a large swath of central Asia until being comprehensively defeated by the Mongols starting from 1219 CE. This brought modern-day Iran, southern Russia, Armenia, Georgia, Azerbaijan and other parts of the Middle East under Mongol rule (Soucek, 2000).

  • Volga Bulgaria: The Turkic state in modern-day Russia centered around the Volga river region was conquered by the Mongols starting in 1223 CE (Vásáry, 2005).

  • Kievan Rus principalities: The conquest of various East Slav principalities, notably Vladimir-Suzdal and Kievan Rus, brought the northwest borders of the empire to the edge of Europe (Martin, 1995).

At the time of Genghis Khan’s death in 1227 CE, the Mongol Empire covered a vast area stretching from the Sea of Japan to the Caspian Sea. The empire controlled the majority of what is now modern day Mongolia, China, Korea, southern Russia, and Central Asia.

Genghis Khan’s last ruling order divided territories between his sons and subordinates. His third son Ögedei was designated as Great Khan to rule the empire. The empire would continue expanding rapidly under Genghis Khan’s successors.


Further Conquests Under Ögedei Khan

Ögedei Khan ruled from 1229-1241 CE and increased Mongol dominance by conquering the remainder of northern China still held by the Southern Song dynasty and pushing the empire’s borders further into Eastern Europe (“Ögedei Khan” 2022). Key campaigns included:

  • Jin dynasty: The Mongols finished off the conquest of northern China, taking the secondary Jin capital Kaifeng by 1233 CE and driving the Jin fully out of mainland China to their coastal holdout on the island of Caizhou, which fell in 1234 CE. This completed the conquest of the Jurchen-Jin (Franke, 1994).

  • Southern Song dynasty: While the Song continued to rule southern China, Mongol armies seized Sichuan province by 1240 CE, opening up the rest of southern China to further conquests (Mote, 2003).

  • Korean peninsula: After the Korean kingdom Goryeo resisted demands to contribute troops, Mongol forces invaded starting in 1231 CE. Korea became a effectively vassal state and contributed forces for later Mongol invasions of Japan (Kim, 2012).

  • Caucasus: Under the Mongol general Subutai, the army carried out raids into the north Caucasus region from 1221-1225 against the neighboring Kievan Rus principalities, followed by the invasion and sacking of several towns in Georgia starting in 1236 CE (Hildinger, 1997).

  • Eastern Europe: In one of the farthest reaching Mongol attacks to date, armies ravaged Polish and Hungarian countryside starting in 1240 CE. Though Ögedei Khan died in 1241 CE forcing the withdrawal of Mongol forces from Central Europe, many towns including Kraków, Sandomierz and Szczytno has been left burned and depopulated (Di Cosmo, Frank & Golden, 2009).


Conquest of Western Asia Under Güyük and Möngke Khan

After Ögedei Khan’s death, there was nearly a decade of disputed succession until his cousin Güyük Khan emerged as Great Khan in 1246 CE, ruling until 1248 CE. Güyük’s older brother Möngke was elected Great Khan in 1251 CE, expanding the empire to its greatest extent and conquering the Abbasid Caliphate based in Baghdad (“Möngke Khan” 2022). The major conquests were:

  • Anatolia: Under Möngke Khan, the Mongols conquered the Sultanate of Rum based in central Anatolia starting in 1243 CE. This brought most of modern-day Turkey under direct Mongol rule. The fall of Aleppo and Damascus in 1260 CE opened Syria and the Levant to Mongol forces as well (Amitai-Preiss, 1995).

  • Abbasid Caliphate: Starting in 1251 CE, Möngke Khan led Mongol troops to directly attack Baghdad and seized it in 1258 CE, ending the Abbasid Caliphate that had ruled most of the Arab world for 500 years. This extended Mongol control through Iraq and beyond (Amitai-Preiss & Morgan, 2007).

  • Ismailis: From 1256-1258 CE, the Mongols successfully besieged several mountain fortresses held by the Nizari Ismaili state (also known as Assassins) in Persia, removing them as an independent threat within territory otherwise controlled by the Mongols (Daftary, 1994).

By 1259-1260 CE under the campaigns of Möngke Khan, virtually all major organized resistance in Eurasia had capitulated to the overwhelming military superiority of the swiftly moving Mongol forces making use of maneuver warfare and siege tactics against which static defenses struggled to respond effectively. Only Japan, Southeast Asia and Western Europe remained mostly beyond the empire’s reach.

Fragmentation of the Empire

Möngke Khan died during further campaigns against the Southern Song dynasty and the succession led to open conflict between his brother and successor as Great Khan Kublai Khan, who established the Yuan dynasty in China, and his younger brother Ariq Böke who claimed authority based in the Mongolian homeland (Rossabi, 1988). This Toluid Civil War left the Mongol Empire split between the territory controlled by Kublai Khan (covering China, Korea and parts of Siberia) and the homeland territory controlled by Ariq Böke consisting of Mongolia and sections of modern-day Kazakhstan, Uzbekistan and Turkmenistan.

Further succession struggles and decentralized rule eventually saw the unified Mongol Empire fade away into a loosely coordinated network of Mongol khanates by around 1300 CE: the Golden Horde comprising parts of Eastern Europe and western Siberia; the Ilkhanate based in Persia, the Chagatai Khanate of central Asia, and the Yuan dynasty in China, Korea and adjacent territories (“Yuan dynasty” 2022). While the later Yuan emperors of China maintained a nominal claim to authority over all of the Mongol khanates, in reality each khanate was independently controlled by its own rulers by the late 13th century CE.

Mongol Empire

Decline of the Mongol Khanates

The once-united Mongol Empire decentralized into four main khanates - each took its own trajectory in ultimately fading from dominance over the next 2 centuries. Several overlapping factors contributed to the waning and eventual collapse of Mongol rule across Eurasia:

Increasing adoption of local culture and customs: As Mongol khans and nobles spent decades and generations ruling over non-Mongol subjects, they increasingly assimilated elements of local culture including language, religion, dress and court rituals. This “going native” diluted traditional Mongol discipline and military prowess (May, 2012).

Backlash and revolt from subject territories: The initial conquest left populations fearful but as Mongol rulers transitioned locally, subject territories eventually rose up against high taxation levels and perceived foreign rule, with revolts toppling Mongol regimes starting in the early 14th century CE (Sinor, 1998).

Climate change and plague: The Black Death pandemic spread to Europe and Central Asia from the early 1340s CE onwards, likely from the Mongol Army inadvertently transmitting plague bacteria in their commerce networks with south China. The loss of millions of lives severely affected economic activity and rulers’ ability to maintain control or field armies (Biraben, 1975).

By roughly 1500 CE, the ruling descendants of Genghis Khan had been overthrown across the extent of the Mongol domains - the last ruling Khanate was the “Moghulistan” branch of the Chagatai Khanate which clung on in nomadic form until the 17th century CE (Millward, 2007). While the unified Mongol Empire lasted just over a century at its peak, the influence of Mongol political and cultural systems lasted for centuries after their decline from dominant power in Eurasia and opened trade routes and facilitated transmission of ideas, goods and technologies across the breadth of the Old World.

Legacy and Impact

The Mongol Empire connected an unprecedented breadth of humanity across culture, religion and geography. The Pax Mongolica facilitated exchange of goods and ideas between the Far East and Europe such as the transmission of Chinese technologies like papermaking, gunpowder weapons and compass navigation to the west, while eastern domains gained new crops, medicine and textile-making techniques in return (Weatherford, 2004). The reopening of the Silk Road trading system provided stimulus to early capitalist commerce between Asia and Europe (Abu-Lughod, 1989).

The Mongol conquest also enabled the first significant cultural contact between European civilization and Chinese civilization, with numerous Christian, Islamic and Buddhist missionaries and intellectuals traversing the Mongol domains to engage with each other’s religious and philosophical concepts for the first time. Within their realms, the Mongols were relatively tolerant of multiple religions. But externally the long decades of conflict and warfare also reinforced Mongol stereotypes across epic poems, art and folklore in Persia, Russia and Eastern Europe as merciless raiders bent on conquest and destruction (“Legacy of the Mongols” 2022).

In the long arc of history however, the Mongol Empire proved to be less a destroyer of civilizations than a transformer. As the domains of Genghis Khan’s descendants adapted to local cultures and they invested in peaceful administration and economic development, the Mongols laid the foundations of the early modern Eurasian world order. Descendant empires like the Timurids of central Asia and the Mughals of India ruled successfully for centuries by blending Mongol and local statecraft into new models of governance and flourishing cosmopolitan culture until being themselves superseded by new waves of developing political forces in the 19th century with the rise of European imperialism and global empire based around industrialization and capitalism.


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