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.
Turkic migration
Qin's campaign against the Xiongnu of 215 BCE kept the Xiongnu at bay, driving them out of and seizing the Ordos region. Problems re-emerged after the Qin Dynasty. The Xiong-nu attacked Shanxi of the Han in 201 BCE. Emperor Gaozu of Han bought them off with jade, silk and a Chinese wife for the Shanyu, or leader. Relations with the Xiongnu continued to be troubled and in 133 BC Emperor Wu of Han proceeded against them with 300,000 men. Eighty-one years and fourteen expeditions later in 52 BC the southern Xiongnu surrendered and the northern desisted from raiding. The Han Dynasty military expeditions continued near the frontier of China, in the Han–Xiongnu War, and in 89 AD the Xiongnu state was defeated and soon ended.