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.
Huns
Since Joseph de Guignes in the , modern historians have associated the Huns who appeared on the borders of Europe in the with the Xiongnu who had invaded China from the territory of present-day Mongolia between the and the . Due to the devastating defeat by the Chinese Han dynasty, the northern branch of the Xiongnu had retreated north-westward; their descendants may have migrated through Eurasia and consequently they may have some degree of cultural and genetic continuity with the Huns. Scholars also discussed the relationship between the Xungnu, the Huns, and a number of people in central Asia were also known as or came to be identified with the name "Hun" or "Iranian Huns", the Chionites, the Kidarites, and the Hephthalites (or White Huns) being the most prominent.