Jüün Ghar was a tribe of the Oyirad Mongols. They maintained the last nomadic empire around Jungaria from the 17th century to the middle 18th century.
List of Jüün Ghar chiefs
The Origin of Jüün Ghar is mysterious. They suddenly emerged in the early 17th century. The royal family was said to be in line of Esen Tayisi. It shared the clan name Choros with the Dörbed and their ancestral legend resembles the Uighur royal family's. The Jüün Ghar and Dörbed are considered as the successor of the Naiman. Jüün Ghar means left (east) hand (wing) in Mongolian although they were in the west end of the Mongols. Maybe they were formed as the left wing of the Dörbed.
The Oyirad Mongols were under the dominion of Jasaghtu Khan of the Khalkha. Khalakhula seems to have resisted against the Khalkha. In 1623 the Oyirad confederation killed Ubasi Khong Tayiji, the first Altan Khan of the Khalkha and gained independence.
In 1636 his son joined the expeditionary force to Tibet against the Karma school led by Güüshi Khan and gave the title Baatur Khong Tayiji. After he returned to Jungaria, Jüün Gjar rapidly gained strength. He made three expeditions against the Kazakhs.
In 1653 his son Sengge succeeded the Jüün Ghar chief, but an internal strife with his half brother Chechen Tayiji involved the Khoshuud. With the supprt of Ochirtu Khan of the Khoshuud, this strife ended with Sengge's victory in 1661. In 1667 he captured Erinchin Lobsang Tayiji, the third and last Altan Khan. He was killed by Chechen Tayiji in a coup in 1670.
Sengge's younger brother Galdan immediately returned to lay life and took revenge on Chechen. As a Buddhist priest, Galdan had been to Tibet at the age of thirteen and had trained under the fourth Panchen Lama and then the fifth Dalai Lama. In 1671 The Dalai Lama bestowed the title of Khong Tayiji on him. He came into conflict with Ochirtu Khan. The victory over Ochirtu in 1677 resulted in the establishment of hegemony over the Oyirad. In the next year the Dalai Lama gave the highest title of Boshughtu Khan to Galdan.