王昭君
The half-Chinese, half-Xiongnu noble Yituzhiyashi (伊屠智牙師), son of Huhanye Chanyu and Wang Zhaojun, became a vocal partisan for Han China within the Xiongnu realm; Bielenstein claims that this led conservative Xiongnu nobles to anticipate a break in the alliance with Han. The moment came when Wang Mang assumed the throne and demoted the Chanyu to a lesser rank; this became a pretext for war. During the winter of 10–11 CE, Wang amassed 300,000 troops along the northern border of Han China, a show of force which led the Xiongnu to back down. Yet when raiding continued, Wang Mang had the princely Xiongnu hostage held by Han authorities executed. Diplomatic relations were repaired when Xian (咸) (r. 13–18 CE) became the chanyu, only to be soiled again when Huduershi Chanyu (呼都而尸) (r. 18–46 CE) took the throne and raided Han's borders in 19 CE.