Xiongnu belt plaque with antlered predator 3rd C. BCE

For about a decade from 60 BCE the Xiongnu went through political chaos and saw nine different rulers. Following the rule of Xuluquanqu Chanyu, the crown passed to Woyanqudi. Woyanqudi's rule was challenged by Huhanye. Huhanye had 50,000 soldiers but seems to have been able to take the throne without bloodshed, Woyanqudi had no desire to engage in civil war and committed suicide as abdication. 

Huhanye's rule was immediately challenged by four others, all declaring themselves as king (Chanyu); Tuqi, Hujie, Cheli, and Wujie. From this point there was official civil war. Tuqi initially attacked Huhanye successfully. Tuqi also attacked Cheli, Wujie, and Hujie. These three were pushed into an alliance for mutual survival and decided on supporting Cheli as Chanyu for his military prowess. 

In 56 BCE Huhanye eventually got the upper hand against Tuqi and Tuqi committed suicide after his defeat. Cheli surrendered to Huhanye in this year. Tuqi's younger cousin, Runzhen, then claimed the title of Chanyu in his place and took domains in the west. And Huhanye's older brother, Zhizhi, also claimed the title while taking domains in the east. 

In 54 BCE Runzhen attacked Zhizhi but was defeated. He was killed and Zhizhi took over his western domains also. 

By 53 BCE Huhanye had been nearly defeated by Zhizhi. He surrendered to the Han government for personal protection. Most of Huhanye's people opposed this, some vocal Xiongnu protests from the 'Wars with the Xiongnu': "This is absolutely preposterous and not tolerable! We Xiongnu revere the chivalrous and brave and it is utterly lowly and despicable to surrender to one's enemies."..."The sons and progenitors of our people shall always preside over our own destiny. Han is a mighty Kingdom - much as they had tried they have not been able to subjugate us. Why do we have to be disloyal to our ancestors and founding fathers by disrupting our established custom? If we were to surrender, it would be the greatest insult to our ancestors."

Despite this, Huhanye still surrendered. The Xiongnu didn't seem to be aware that the Han were starting to face similar internal strife problems. Huhanye offered himself as a vassal subject, but the Han refused and instead elevated him to the position of a state dignitary. He would be above Han's vassal lords, he didn't have to kneel to the Han Emperor, and neither he nor his descendants would be required to pay tribute. Initially weaker than Zhizhi, with Han's support Huhanye's southern faction became more formidable. The schism between the Northern and Southern Xiongnu had begun. 

-Wars with the Xiongnu according to Zizhi Tongjian, translated by Joseph P. Yap 

Xiongnu belt plaque with crouching composite predator with antlers decorated with raptor heads. Gold with turquoise inlay. Ca. 3rd century BCE. Excavated at Aluchaideng, Inner Mongolian Autonomous Region. Collection of the Inner Mongolia Museum, Hohhot. 

Source:

https://www.researchgate.net/figure/Gold-ornament-with-turquoise-inlay-Excavated-from-Aluchaideng-Inner-Mongolia-5th-3rd_fig3_350125071

https://twitter.com/Peteto90/status/1187163926741635072

http://www.silkroadfoundation.org/newsletter/vol11/SilkRoad_11_2013_zhang.pdf

Quote:

Wars with the Xiongnu according to Zizhi Tongjian, translated by Joseph P. Yap