The ambassadors of Wang Mang, on his assumption of the imperial throne in CE 9, had visited the southwestern tribes (in modern Guizhou, Yunnan, and southwestern Sichuan), whose chieftains the Han dynasty had largely granted the titles of princes.
Wang's new seals had demoted them to the titles of marquesses.
One of the more powerful ones, Han, the Prince of Juting, had become so angry that he severed relations with the Xin government.
Wang had instructed the local prefect Zhou Xin to use trickery to kill Han.
In response, Han's brother Cheng had started a rebellion, killing Zhou, and had begun a campaign of harassment against the Xin borders.
The prefecture of Yizhou (modern northeastern Yunnan) has become corrupt by 16, and yet Juting remains powerful.
Wang commissions two generals, Lian Dan and Shi Xiong, who are initially successful against Juting, but soon become caught in problems with food supply and plagues.
However, Wang continues to refuse to reinstitute the Han system of using awards to buy the submission of southwestern tribes.