 In 1271 the Yuan dynasty (1271–1368) was founded by Kublai Khan and based in modern-day Beijing, but lost control of the Tarim Basin and Zungharia to Ariq Böke, ruler of Mongolia.The Chagatai Khanate was a Mongol and later Turkicized khanate that comprised the lands ruled by Chagatai Khan, second son of Genghis Khan, and his descendants and successors.Initially it was a part of the Mongol Empire, but it became a functionally separate khanate with the fragmentation of the Mongol Empire after 1259.