While the Turks were settled in the Ordos region (former territory of the Xiongnu), the Tang government took on the military policy of dominating the central steppe. The Tang dynasty (along with Turkic allies) conquered and subdued Central Asia during the 640s and 650s. During Emperor Taizong's reign alone, large campaigns were launched against not only the Göktürks, but also separate campaigns against the Tuyuhun, the oasis states, and the Xueyantuo. Under Emperor Taizong, Tang general Li Jing conquered the Eastern Turkic Khaganate. Under Emperor Gaozong, Tang general Su Dingfang conquered the Western Turkic Khaganate, an important ally of the Byzantine empire. After these conquests, the Tang dynasty fully controlled the Xiyu, which was the strategic location astride the Silk Road. This led the Tang dynasty to reopen the Silk Road, with this portion named the Tang-Tubo Road ("Tang-Tibet Road") in many historical texts.