Ordos Plateau
In Chinese accounts, the Xiongnu first appear at Ordos in the "Yizhoushu" and "Shanhaijing" during the Warring States period before it was occupied by Qin and Zhao. It is generally thought to be their homeland, however when exactly they came to occupy the region is unclear, and it might have been much earlier than traditionally thought, as suggested by archaeological finds. As the Xiongnu expanded southward into Yuezhi territory around 160 BC under their leader Modun, the Yuezhi in turn defeated the Sakas (Scythians) and pushed them away at the Issyk Kul. It is thought the Xiongnu also occupied the Ordos area during the same period, when they came in direct contact with the Chinese. From there, the Xiongnu conducted numerous devastating raids into Chinese territory (167, 158, 142, 129 BC). The Han Dynasty started to fight the Xiongnu in the 2nd century BC under emperor Han Wudi, and colonized the area of the Ordos under Shuofang commandery in 127 BC. Prior to the campaign, there were already commanderies established earlier by Qin and Zhao until they were overrun by the Xiongnu in 209 BC.
Jiangqu
In 51 BCE a pretender to the Xiongnu's throne Huhanye re-established the "heqin" peace and kinship treaty with the Han empire, and fled to China with a fraction of the Xiongnu, partitioning the Xiongnu state into the Northern Xiongnu and Southern Xiongnu, and establishing a new polity allied with China. The Southern Xiongnu retained a title "Chanyu" for their leader, and started a new dynastic line beginning with Huhanye. Huhanye himself belonged to the 8th generation of the Maodun line of the dynastic paternal Luanti tribe, the tribe Qiang ("Kiyan") was a maternal dynastic tribe of the Southern Xiongnu. During the existence of the Southern Xiongnu state, its Xiongnu population greatly varied depending on the events in the steppe, at times it was swelling with numerous Xiongnu tribes fleeing trouble events, and at times it was losing Xiongnu tribes when they returned after return of peaceful times. The Chinese policies also affected the in and out flows. Until the event with Zhang Xiu in 179 CE, the Southern Xiongnu continued electing their Chanyus without explicit Chinese intervention, Jiangqu was the first Southern Xiongnu Chanyu who broke the traditional Xiongnu succession laws, undermining the integrity of the Southern fraction. Tribes that did not want to recognise a non-eligible leader either revolted against him, or left the area under his control.