Chizhishizhuhou Chanyu
The southern Xiongnu were a branch of the eastern Xiongnu that followed the rebellious pretender Huhanye and in 51-53 BC moved en masse within the Han borders under protection of Chinese. Since the times of Huhanye, the status of the southern Xiongnu was loyal allies of the Han Dynasty. The southern Xiongnu enjoyed material support of the old "heqin" treaty, and in return guarded the Chinese northern borders and participated in the Chinese external and internecine conflicts as long as the Chinese court respected their independence. However, when the Han imperial court attempted to appoint an ineligible for the crown Western Jükü-Prince Yufuluo from ineligible Right Wing as a Chanyu, instead of respecting the traditional election, the southern Xiongnu dissented and elected a lawful alternate Hyuibu Gudu-heu. Later they expelled Yufuluo, who had to seek safety in exile at the Han imperial court.
Han–Xiongnu War
The Southern Xiongnu—who had been situated in the Ordos region since about 50 AD—remained within the territory of the Han empire as semi-independent tributaries. They were dependent to the Han empire for their livelihood as indicated by a memorial from the Southern Chanyu to the Han court in 88 AD. Following the military successes against the Xiongnu, General Ban Chao was promoted to the position of Protector General and stationed in Kucha in 91 AD. At the remote frontier, Ban Chao reaffirmed absolute Han control over the Western Regions from 91 AD onwards.