The Zunghar Khanate was a nomadic power on the Eurasian steppe. It covered the area called Dzungaria and stretched from the west end of the Great Wall of China to present-day eastern Kazakhstan, and from present-day northern Kyrgyzstan to southern Siberia (most of this area is part of Xinjiang nowadays).
In 1678 Galdan received from the Dalai Lama the title Boshogtu Khan. This confirmed the Zunghars as the new leading tribe of the Oirats. However, the Zunghar rulers bore title of Khong Tayiji (originally meaning crown prince from the Chinese word, Huang Taizi, which also means the same thing) while their state was often called Zunghar Khanate. After the deaths of Galdan Boshogtu Khan and Tsewang Rabtan, the Khanate began to decline; it was annexed by the Qing Dynasty in 1756-59.
Read more about Zunghar Khanate: Etymology, Leaders of The Zunghar Khanate