Xiongnu
The Xiongnu () were a confederation of nomadic peoples who, according to ancient Chinese sources, inhabited the eastern Asian Steppe from the 3rd century BC to the late 1st century AD. Chinese sources report that Modu Chanyu, the supreme leader after 209 BC, founded the Xiongnu Empire.
Wusun
The Wusun originally lived between the Qilian Mountains and Dunhuang (Gansu) near the Yuezhi. Around 176 BCE the Yuezhi were raided by the Xiongnu, who subsequently attacked the Wusun, killing their king and seizing their land. The Xiongnu adopted the surviving Wusun prince and made him one of their generals and leader of the Wusun. Around 162 BCE the Yuezhi were driven into the Ili River valley in Zhetysu, Dzungaria, and Tian Shan, which had formerly been inhabited by the Saka (Scythians). The Wusun then resettled in Gansu as vassals of the Xiongnu. In 133–132 BCE, the Wusun drove the Yuezhi out of the Ili Valley and settled the area.