Kublai Khan Takes the Great Khagan Throne

Timeline

1. 1259Diaoyu Fortress · ChongqingIn 1259 the fourth great khagan Möngke died of illness during his campaign against the Southern Song, creating a vacuum at the top of the Mongol Empire. By nomadic tradition, a new great khagan had to be chosen by the princes and noyans at a kurultai, and the succession crisis quickly emerged.
2. 1260Kaiping · Inner MongoliaIn 1260 Kublai, then fighting in the Central Plains, learned of Möngke's death but did not immediately return north; instead he convened a kurultai at Kaiping, won the support of Han-land princes and ministers, and proclaimed himself great khagan with the era name Zhongtong. This marked the beginning of the Mongol Empire's center of power shifting toward the Han lands.
3. 1260Karakorum · MongoliaAfter Kublai's accession, his brother Ariq Böke was enthroned at Karakorum, the traditional Mongol political center, by some princes and noyans, and also claimed the title of great khagan. Neither side recognized the other's legitimacy, and a civil war within Tolui's line erupted, plunging the Mongol Empire into division and confrontation.