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.
Oghuz Turks
During the 2nd century BC, according to ancient Chinese sources, a steppe tribal confederation known as the Xiongnu and their allies, the Wusun (probably an Indo-European people) defeated the neighboring Yuezhi and drove them out of western China and into Central Asia. Various scholarly theories link the Xiongnu to Turkic peoples and/or the Huns. The first usage of the word "Oghuz" appears to have been the title of "Oğuz Kağan", given in 220 BC to the Xiongnu king Modu Shanyu (or Mau-Tun), who founded the Xiongnu Empire. According to a controversial theory with few scholarly adherents, one transliteration of Yuezhi, as "Hu-chieh", may refer to the Turkic Uyghurs. However, the Yuezhi are widely believed to have spoken an Indo-European language or languages.