What Was the Mongol Empire? Conquest, Trade, and a Vast Eurasian Realm
By the BrainSnail editorial team. How these articles are written and checked, and how to tell us when one is wrong.
The Mongol Empire was a vast thirteenth-century empire created by Mongol rulers who conquered territories across much of Asia, the Middle East, and eastern Europe. At its height, it became the largest contiguous land empire in history.
The grasslands where it began
The story begins on the grasslands of Mongolia, where pastoral communities lived in tribes and shifting alliances. Temujin, later known as Genghis Khan, defeated rivals and united many Mongol groups under his leadership. In 1206, an assembly recognised him as the supreme ruler of the Mongols, giving him the title commonly translated as Genghis Khan.
Understanding the Mongol Empire means looking beyond one sudden wave of conquest. Genghis Khan created military and political systems that could organise people from different clans, reward loyalty, move armies quickly, and absorb useful skills from conquered societies. Mounted archers, disciplined units, intelligence gathering, and flexible tactics helped Mongol forces defeat much larger opponents.
Conquests connected distant parts of Eurasia
Genghis Khan and his successors expanded into northern China, Central Asia, Persia, Russia, and other regions. Mongol armies could be extremely destructive, especially when cities resisted. Sieges, massacres, forced movement, and warfare caused enormous suffering. At the same time, Mongol rulers often kept local administrators, engineers, merchants, and religious specialists when their skills were useful.
After Genghis Khan died in 1227, expansion continued under his descendants. The empire eventually developed into several major khanates ruled by different branches of the family. When revising the Mongol Empire, remember that it did not remain one centrally controlled state forever. Its political unity weakened even while Mongol-ruled regions remained powerful.
Mongol rule changed trade and communication
The Mongol conquests brought large stretches of Eurasia under related ruling houses. Routes used by merchants, diplomats, craftspeople, and travellers could cross territories with stronger political connections than before. Mongol authorities maintained relay stations and protected some important trade routes, helping messages and goods move across long distances.
This greater movement also carried consequences. Technologies, ideas, artistic influences, and knowledge travelled between regions, but diseases could move along the same networks. A complete answer to what the Mongol Empire was therefore includes both connection and destruction. The empire opened paths for exchange while its wars also transformed populations, cities, and political systems across Eurasia.
Governing what they had conquered
Ruling an empire that stretched from Korea to Hungary needed more than cavalry. The Mongols kept a body of law and decrees known as the Yasa, and took a census of conquered populations so that taxes and military service could be assessed. They tolerated most religions, partly from conviction and partly because it kept subject peoples quiet, and they promoted talented administrators regardless of origin, so a Persian might run finances in China while a Chinese engineer built siege engines in Persia.
Paper money circulated in Mongol China, and the postal relay system, the yam, let a rider cover well over 300 kilometres a day by changing horses at stations. By the 1290s the four khanates, the Yuan in China, the Ilkhanate in Persia, the Chagatai in Central Asia and the Golden Horde in Russia, were effectively separate states, and the empire's story becomes four stories.
How historians know about the Mongols
The Mongols wrote relatively little about themselves, so historians piece the empire together from many sources in many languages. The most important Mongol account is The Secret History of the Mongols, written in the thirteenth century, which tells the story of Temujin's family, rivals and rise to power. It survives mainly in a version written in Chinese characters that record the Mongolian sounds. It mixes history with legend and family tradition, so historians read it carefully, but it gives a rare view of the steppe world from the inside.
Many other sources come from people the Mongols conquered or met. Rashid al-Din, a minister of the Mongol rulers of Persia, compiled a huge world history in the early fourteenth century using Mongol informants. Chinese officials produced an official history of the Yuan dynasty. European travellers left eyewitness reports, including the friars John of Plano Carpini and William of Rubruck, who visited the Mongol court in the 1240s and 1250s, and Marco Polo's account of China. Each source has its own bias, from conquered peoples' hostility to court flattery, so historians compare them against one another and against archaeology.
Where the conquests stopped
In 1241 Mongol armies crushed a Polish and German force at Legnica and a Hungarian army at Mohi, and western Europe seemed open to them. Yet by 1242 they had withdrawn. A long-standing explanation is the death of the Great Khan Ogedei in December 1241, which drew leading princes back towards Mongolia to settle the succession. Historians also point to other possible factors, including the limited grazing on the Hungarian plain for the huge numbers of horses a Mongol army needed, and a spell of wet weather that turned ground to marsh. Which reason weighed most is still debated.
Elsewhere the limits were set by battle and by the sea. In 1260 a Mongol force was defeated at Ain Jalut in Palestine by the Mamluks of Egypt, a battle often seen as the moment their advance in the Middle East was halted, made easier because much of the main army had withdrawn after another khan's death. In China, Kublai Khan launched invasions of Japan in 1274 and 1281. Both failed, and storms wrecked much of the invading fleet, especially in 1281. The Japanese later called such storms kamikaze, divine winds, a name borrowed in the Second World War for suicide pilots.
The siege of Caffa and the road to the Black Death
In 1346 an army of the Golden Horde, led by the khan Jani Beg, was besieging Caffa, a Genoese trading port on the coast of Crimea, when plague broke out among the besiegers. A notary from Piacenza called Gabriele de' Mussis later wrote that the Mongols catapulted infected corpses over the walls, spreading the disease to the defenders. Genoese ships leaving the Black Sea then carried plague towards the Mediterranean, and it reached Sicily in 1347. Within a few years the Black Death had killed perhaps a third or more of Europe's population, along with huge numbers in the Middle East and North Africa.
Historians treat the corpse story with care. De' Mussis was probably not an eyewitness, and plague was already moving through the region along trade routes, carried by rats, fleas and people, so ships from several ports could have brought it west. Where the epidemic began has been clarified by ancient DNA. Researchers studying burials in the Chu valley of present-day Kyrgyzstan, where gravestones from 1338 and 1339 mention a pestilence, recovered the plague bacterium and found that it sat close to the root of the strains behind the Black Death. The routes that carried silk and envoys across Mongol Eurasia may well have carried the disease too.
The takeaway
The Mongol Empire was a huge Eurasian empire built through the conquests of Genghis Khan and his successors. Its armies changed political borders, while Mongol rule also encouraged long-distance movement of people, goods, information, and ideas across territories that had previously been more divided.