Ariq Böke
Kublai Khan was campaigning against the southern Song in 1260 when he received news that Ariq Böke was challenging him for the succession of the throne. Ariq Böke formed alliances with powerful members of the Mongol nobility to endorse him as a candidate for Great Khan. Most of Möngke's immediate family supported Ariq Böke including the member of Ögedei, Chagatai and Jochi. Kublai withdrew from the Song and mobilized his troops to fight Ariq Böke. In China, Kublai summoned a kurultai at Kaiping, where he was elected Great Khan. This was the first kurultai to proclaim a Great Khan outside the Mongol homeland or Central Asia. Ariq Böke convened his own kurultai in Karakorum that proclaimed him Great Khan a month later, creating two rival claimants for the throne. Hulagu embarked for Mongolia to attend the kurultai, but the Mamluk defeat of the Mongols at the Battle of Ain Jalut forced him to retreat back to the Middle East. Berke capitalized on the Mamluk victory by invading the Ilkhanate, beginning the Berke–Hulagu war.