The Mongol Empire split into four major khanates: the Golden Horde, the Chagatai Khanate, the Ilkhanate, and the Yuan dynasty. This fragmentation became clear after the death of Möngke Khan in 1259 and the succession struggles that followed.
The Golden Horde controlled much of the Mongol realm in Eastern Europe and the western steppe. The Chagatai Khanate ruled large parts of Central Asia. The Ilkhanate, founded by Hülegü, dominated Iran, Iraq, and neighboring regions. Kublai Khan’s Yuan dynasty governed China and retained the imperial capital at Dadu, modern Beijing.
These divisions were connected to the empire’s dynastic structure, in which different branches of Genghis Khan’s family held extensive territories. Civil wars, rival claims to the title of Great Khan, and conflicts between regional rulers weakened central authority. By the late thirteenth century, the four khanates were functionally independent, even though the Yuan emperors continued to claim nominal supremacy.
The answer is four when discussing the empire’s principal post-fragmentation divisions. Later, each khanate itself broke into additional states, which is why lists of Mongol successor kingdoms can contain many more than four names.