In 1328, when Yesün Temür Khan died, a civil war known as the War of the Two Capitals erupted between Shangdu-based Ragibagh and Dadu-based Tugh Temür. The former was a son of Yesün Temür and was backed up the former Yesün Temür administration led by Dawlat Shah, and the latter was Kuśala's younger brother who was supported by the former Khayishan faction led by the Qipchaq commander El Temür and the Merkit commander Bayan, a governor in Henan. This ended in the victory of Tugh Temür since he secured support from most of the princes, aristocrats and warlords in the south of the Gobi Desert. Tugh Temür summoned his brother to come to Dadu.