Wuhuan had become somewhat of a dual…

Wuhuan had become somewhat of a dual vassal to both the Han and the Xiongnu during the late Han Dynasty, and, under a policy in effect since 121 BCE, is supposed to pay Xiongnu tributes in textile and leather.

Should Wuhuan fail to pay the tributes, Xiongnu forces kidnap Wuhuan women as hostages.

The first sign of irritation with Wang Mang’s policies had come sometime before 10, by which time the Xin director of Wuhuan affairs had informed the Wuhuan tribes not to pay further tribute to Xiongnu.

In response, the Xiongnu mount a punitive military action against Wuhuan, taking hostage about one thousand women and children.

At Wang Mang's orders, the Xiongnu are later forced to return the Wuhuan hostages.