Toluid Civil War

The Toluid Civil War was fought between Kublai Khan and his younger brother, Ariq Böke, from 1260 to 1264.  Möngke Khan died in 1259 with no declared successor, precipitating infighting between members of the Tolui family line for the title of Great Khan that escalated to a civil war. The Toluid Civil War, and the wars that followed it (such as the Berke–Hulagu war and the Kaidu–Kublai war), weakened the authority of the Great Khan over the Mongol Empire and split the empire into autonomous khanates.