The Chagatai Khanate (Mongolian: Tsagadai Khan Uls/Цагадайн улс) was a Turko-Mongol khanate that comprised the lands ruled by Chagatai Khan, second son of Genghis Khan, and his descendents and successors. Initially it was considered a part of the Mongol Empire, but it later became fully independent.
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.
The khanate lasted in one form or another from 1220s until the late 17th century, although the western half of the khanate was lost to Tamerlane in the 1360s. The eastern half remained under Chagatai khans who were, at times, allied or at war with Timur's successors. Finally, in the 17th century, the remaining Chagatai domains fell under the theocratic regime of Apaq Khoja and his descendants, the Khojijans, who ruled East Turkestan under Dzungar and Manchu overlordships consecutively.
Read more about Chagatai Khanate: Formation, The Chagatai Khanate After Chagatai, End of Chagatayid Rule in Transoxiana, Chagatayid Rule Continued in East Turkestan, End of Chagatayid Rule, List of Rulers