The Chagatai Khanate (Mongolian: Tsagadain Khaant Uls/Цагаадайн Хаант Улс) was a khanate that comprised the lands ruled by Chagatai Khan, second son of Genghis Khan, and his descendents and successors. Initially it was a part of the Mongol Empire, it became a functionally separate khanate with the fragmentation of the Mongol Empire after 1259. The Chagatai Khanate recognized the nominal supremacy of the Yuan dynasty in 1304, but the khanate became split into two parts, the Western Chagatai Khanate and Moghulistan, in the mid-14th century.