[1][2] In 109, the Southern Chanyu with a number of Wuhuan and Xianbei rebelled and, by winter, controlled a large area of the northern commanderies near the Yellow River.
Geng Kui, who is named as being the Governor of Liaodong at the time, and Liang Qin, the last Protector General of the Western Regions who was hurriedly sent with 8,000 men bore the brunt of the fighting.
In the autumn they defeated the troops of Yunzhong Commandery and killed Grand Administrator Cheng Yan, and besieged the Colonel Protector of the Wuhuan in the city of Macheng.
Geng Kui, who was now entitled the new General Who Crosses the Liao, managed with a large army to drive off, but not defeat the Xianbi and relieve the siege of Macheng.
However, the Xianbi, from this time on became more aggressive regularly raiding along the frontier with a force said to number tens of thousands of mounted archers.