Dou Xian
The southward migration of nomadic tribes into the lands around the Yellow River had been ongoing since the Eastern Han dynasty for several reasons. the Han dynasty's defeated of the Xiongnu confederation in the Han–Xiongnu War by Han General Dou Xian led to the Han dynasty deporting the Southern Xiongnu along with their Chanyu into northern China. In 167 AD, Duan Jiong conducted an anti-Qiang campaign and massacred Qiang populations as well as settled them outside the frontier in northern China.