Modu Chanyu
The Saka were pushed out of the Ili and Chu River valleys by the Yuezhi. An account of the movement of these people is given in Sima Qian's "Records of the Grand Historian". The Yuehzhi, who originally lived between Tängri Tagh (Tian Shan) and Dunhuang of Gansu, China, were assaulted and forced to flee from the Hexi Corridor of Gansu by the forces of the Xiongnu ruler Modu Chanyu, who conquered the area in 177–176 BC. In turn the Yuehzhi were responsible for attacking and pushing the Sai ("i.e." Saka) west into Sogdiana, where, between 140 and 130 BCE, the latter crossed the Syr Darya into Bactria. The Saka also moved southwards toward the Pamirs and northern India, where they settled in Kashmir, and eastward, to settle in some of the oasis-states of Tarim Basin sites, like Yanqi (焉耆, Karasahr) and Qiuci (龜茲, Kucha). The Yuehzhi, themselves under attacks from another nomadic tribe, the Wusun, in 133–132 BC, moved, again, from the Ili and Chu valleys, and occupied the country of Daxia, (大夏, "Bactria").