 Complete the following phrase:  During the Han Dynasty, one of Kazakhstans ancestors, the Wusun, practiced heqin intermarriage with the Chinese, marking the beginning of relations. During the rule of Emperor Wu of Han, Zhang Qian was the official dispatched to the Western Regions 西域 xiyu to help the Wusun against the Xiongnu. Since the Wusun did not want to cooperate with the Xiongnu, they allied with the Han dynasty to defeat the Xiongnu 