In 937, Duan Siping overthrew the Nanzhao and established the Dali Kingdom. The kingdom was conquered by the Mongol Empire in 1253 after Dali King Duan Xingzhi defected to the Mongols. The Duans incorporated into the Mongol dominion as Maharajas of the new province. The Mongolian prince sent to administer the region with them was killed. In 1273, Kublai Khan reformed the province and appointed the semu Ajall Shams al-Din Omar as its governor. The Yunnan Province during the Yuan dynasty included significant portions of Upper Burma after the First Mongol invasion of Burma in the 1270s and 1280s. With the fall of the Yuan dynasty in 1368, the Ming dynasty destroyed the Yuan loyalists led by Basalawarmi and the remnants of the House of Duan in the Ming conquest of Yunnan by the early 1380s.