The forces that led to the fall of the Mongols were the foreign administrators of the far-flung empire and the internal bickering of the Mongol khanates, according to Encyclopaedia Britannica. Rebellion by the more powerful subjugated peoples, and the inability of the Mongols to unify, caused the empire to disintegrate into a loose confederation.
In the 12th century, Genghis Khan achieved supremacy within the All Mongol League and was proclaimed khan. Early in the 13th century, his military campaigns created a vast empire from northern China to European Russia. The key to the Mongol attacks was skilled archers on horseback, but they also learned how to besiege cities that opposed them. Subsequent khans chosen from among Genghis Khan's sons and relatives continued to expand the empire. It reached its zenith under one of Genghis Khan's grandsons, Kublai Khan, who defeated the Song dynasty in China and even attempted unsuccessful invasions of Japan and Indonesia.
The dividing of the empire between Kublai Khan's four sons began its disintegration. However, the Mongol policy of administrating the empire through conquered subjects hastened the fragmentation. In 1368, China's Ming dynasty successfully rebelled against the Mongols, and in 1380, a Russian alliance defeated their conquerors. Persia, Belarus and Ukraine all overthrew the Mongols in the 14th century. The empire continued to shrink until the 15th century, when it encompassed little more than the Mongol homeland.