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. Like the earlier Han Dynasty, the Tang Dynasty, along with Turkic allies like the Uyghurs, 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, and the Xueyantuo. Taizong also launched campaigns against the oasis states of the Tarim Basin, beginning with the annexation of Gaochang in 640. The nearby kingdom of Karasahr was captured by the Tang in 644 and the kingdom of Kucha was conquered in 649.