The Kokonor Mongols (Tib. sTod-sog) are the descendents of the Khoshut (Qoshot) Western Mongols, originally from East Turkestan, who defeated the Tsang forces of Central Tibet in the seventeenth century and gave temporal rule over Tibet to the Fifth Dalai Lama.
There are several groups of these Mongols. One is centered around Maqu County 玛曲县 in the extreme southwest corner of Gansu 甘肃. They have four monasteries, speak only Tibetan and no Mongolian, and at present study at Labrang Monastery. Another group is centered around Henan Mongol Autonomous County 河南蒙古族自治县, in Qinghai 青海 just across the provincial border from Maqu. They have five or six monasteries, still speak Mongolian, and at present study at Kumbum Monastery. Before 1949, there was no division between them. Another group of Kokonor Mongols lives in Subei Mongol Autonomous County 肃北蒙古族自治县, south of Dunhuang 敦煌 in far western Gansu.