Ili River
According to the Han Chronicles In 132BCE the Yuezhi were driven out of the Ili River valley by the Wusun. They fled south from the Ili river area, by-passed the urban civilization of the Dayuan in Ferghana, and re-settled north of the Oxus in Bactria, definitively cutting Dayuan from contact with the Greco-Bactrian kingdom. The Yuezhi would further expand southward into Bactria proper around 125 BCE, and then going on to form the Kushan Empire in the 1st century CE.