Region of Lake Balkash and the Ili River
Click on image to enlarge it.

After the Yuezhi were attacked and defeated by the Xiongnu in 162 BCE, they migrated to the Ili Valley where they remained until 132 BCE. In 132 BCE, the Yuezhi were attacked in the Ili Valley by the Wusun. The Yuezhi then moved to Soghdia and the Wusun took their place in the valley.