The Wusun were an Indo-European semi- nomadic steppe people mentioned in Chinese records from the 2nd century BC to the 5th century AD.
The Wusun originally lived between the Qilian Mountains and Dunhuang ( Gansu) near the Yuezhi. Around 176 BC the Yuezhi were raided by the Xiongnu, subsequently attacking the Wusun, killing their king and seizing their land. The Wusun prince was subsequently adopted by the Xiongnu ruler and made a Xiongnu general and leader of the Wusun. After the Yuezhi around 162 BC were driven into the Ili Valley of Zhetysu, Dzungaria and Tian Shan formerly inhabited by the Sai ( Scythians), the Wusun resettled Gansu as vassals of the Xiongnu. In 133-132 BC, the Wusun drove the Yuezhi from the Ili Valley and settled the area. They subsequently became close allies of the Han dynasty and a powerful force in the region for several centuries. Pressured by the Rouran, the Wusun are last mentioned by the Chinese as having settled the Pamir Mountains in the 5th century AD. They possibly became subsumed into the later Hephthalites.