The Chagatai Khanate or Chagatai Ulus (Mongolian: Цагаадайн улс; Uzbek: Chigʻatoy ulusi; Chinese: 察合台汗國; Persian: خانات جغتای‎) 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. At its height in the late 13th century, the khanate extended from the Amu Darya south of the Aral Sea to the Altai Mountains in the border of modern-day Mongolia and China, roughly corresponding to the defunct Qara Khitai Empire. Initially the rulers of the Chagatai Khanate recognized the supremacy of the Great Khan, but by the reign of Kublai Khan, Ghiyas-ud-din Baraq no longer obeyed the emperor's orders. During the mid-14th century, the Chagatais lost Transoxania to the Timurids. The reduced realm came to be k