Tughlugh Timur
Kashgar historian Muhammad Imin Sadr Kashgari recorded Uyghurstan in his book "Traces of Invasion" ("Asar al-futuh") in 1780. Power in the western half devolved into the hands of several tribal leaders, most notably the Qara'unas. Khans appointed by the tribal rulers were mere puppets. In the east, Tughlugh Timur (1347–1363), an obscure Chaghataite adventurer, gained ascendancy over the nomadic Mongols, and converted to Islam. In 1360, and again in 1361, he invaded the western half in the hope that he could reunify the khanate. At their greatest extent, the Chaghataite domains extended from the Irtysh River in Siberia down to Ghazni in Afghanistan, and from Transoxiana to the Tarim Basin.