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.
Xiongnu
An early reference to the Xiongnu was by the Han dynasty historian Sima Qian who wrote about the Xiongnu in the "Records of the Grand Historian" ( BC), drawing a distinct line between the settled Huaxia people (Chinese) to the pastoral nomads (Xiongnu), characterizing it as two polar groups in the sense of a civilization versus an uncivilized society: the Hua–Yi distinction. Pre-Han sources often classify the Xiongnu as a "Hu" people, which was a blanket term for nomadic people in general; it only became an ethnonym for the Xiongnu during the Han.