From confederation to empire
The Mongol Empire began in 1206, when Temujin was recognized as Genghis Khan by an assembly of Mongol leaders. At that time the Mongols were one group among several on the steppe. What was new was the unified political and military organization he built, which drew in many peoples under a single ruler.
The next few decades saw rapid expansion. Mongol armies attacked the Jin dynasty in northern China, the Western Xia, and states in Central Asia. After Genghis Khan died in 1227, his third son Ogedei was chosen as Great Khan. Under Ogedei and later rulers, campaigns reached Persia, the Caucasus, Russian principalities and parts of Eastern Europe. In East Asia, the conquest of southern China was completed under Kublai Khan in the 1270s.
Why the Mongols were effective
Historians usually point to a combination of factors rather than one cause:
- Highly mobile cavalry, with riders who could shoot from horseback and travel with spare mounts.
- Discipline and a command structure that let separate armies coordinate over long distances.
- Intelligence gathering and willingness to adopt new methods, such as siege engineering from conquered peoples.
- Divisions among their opponents, which sometimes made it hard to respond together.
- The use of terror as a strategy, in which cities that resisted could be treated harshly while those that submitted were often spared.
None of these explains everything, and historians continue to debate the weight of each.
Scale, in general terms
The empire at its height is usually described as the largest contiguous land empire in history. It stretched across a large part of Eurasia, from the Pacific coast in the east to Eastern Europe and the Middle East in the west. Exact area and population numbers are estimates that depend on definitions and sources, so it is safer to describe the scale in broad terms than to quote a single figure.
Governing a huge territory
The Mongols ruled many different peoples with different languages and religions. In general, the court tolerated many faiths and employed administrators, scribes and advisers from conquered regions. Taxes, census-taking and law were adapted to local conditions. Communication across such distances depended on the Yam postal system, a network of relay stations that carried officials and messages. The relative security of the main routes also helped long-distance trade, which is often linked to the Silk Road trade, though this should not be overstated, since trade existed long before and continued after.
The empire also helped spread goods, technologies and ideas, but it also disrupted societies, and in some regions the period is remembered mostly for destruction. Both parts matter.
Succession and division
The empire did not stay united for long. Disputes over succession are a recurring theme. After the reign of Mongke Khan in the mid-thirteenth century, a conflict between Kublai and his brother Ariq Boke ended with Kublai’s victory, but by then the empire’s unity was under strain. Over time, four main regions emerged under descendants of Genghis Khan:
- The Yuan dynasty in China and Mongolia, founded by Kublai Khan, with its main capital in what is now Beijing.
- The Chagatai Khanate in Central Asia.
- The Ilkhanate in Persia and neighboring areas.
- The Golden Horde (also called the Khanate of Kipchak) across the western steppe and Russian lands.
These states went their own ways and sometimes fought one another. In many cases the ruling families adopted local religions, for example Islam in several western khanates and Buddhism among the Mongols in the east, and blended with local populations.
The end of the empire
The successor states ended at different times and for different reasons. The Yuan dynasty fell in 1368, when Chinese rebels established the Ming dynasty, and the Mongol court withdrew to the steppe. The Ilkhanate fragmented in the fourteenth century. The Golden Horde broke into smaller khanates over a longer period, with some lasting until the fifteenth and sixteenth centuries and later. Dates and details differ by region, so a broad statement is safer than a specific one.
Karakorum and the homeland
For a time, the empire’s administrative center was Karakorum in central Mongolia. Later khans shifted their attention elsewhere, and the Mongolian homeland became, in effect, one region among several. The empire’s legacy also looks different from different places, and in Mongolia it is a foundation of national memory, as explained in the article on Genghis Khan.
Sources and caution
The main written sources include the Secret History, Chinese dynastic histories, Persian chronicles and the accounts of travelers. They were written by different people with different aims, so figures such as casualties or army sizes are often unreliable. When you read a precise number about the Mongols, check where it comes from.