Han–Xiongnu War
In 119 BC, when the Xiongnu suffered a catastrophic defeat by the Han armies, the Chanyu moved his court (located in present-day Inner Mongolia) to another location north. This had the desired result that the Xiongnu were separated the Wuhuan people, which also prevented the Xiongnu from exacting many resources from the Wuhuan. The Han court placed the Wuhuan in tributary protection and resettled them in five northeastern commandaries, namely Shanggu, Yuyang, Youbeiping (present-day Hebei), Liaoxi, and Liaodong (present-day Liaoning). A new office, the Colonel-Protector of the Wuhuan, was established (near present-day Beijing) in order to prevent contact between the Wuhuan with the Xiongnu and to use them to monitor the Xiongnu activities. Nevertheless, the effective Han control over the Wuhuan was lacking through much of the Western Han period, since the Xiongnu had considerable military and political influence over the Wuhuan while relations between the Wuhuan and Han often remained strained at best. This can be exemplified by a situation in 78 BC, when the Xiongnu led a punitive campaign against the Wuhuan, resulting in General Fan Mingyou (范明友) leading a Han army to impede further incursions. When they learned that the Xiongnu had left by the time the army arrived, the Han court ordered Fan to attack the Wuhuan instead, killing 6000 Wuhuan men and three chieftains, since the Wuhuan had recently raided Han territory. Only in 49 AD, when 922 Wuhuan chieftains submitted during Emperor Guangwu's reign, did many of the Wuhuan tribes come under tributary system of the Han empire. The Han court provided for the Wuhuan and in return the Wuhuan tribes guarded the Han frontier against the Xiongnu and other nomadic peoples.
Xiongnu
Chinese sources link the Tiele people and Ashina to the Xiongnu, not all Turkic peoples. According to the "Book of Zhou" and the "History of the Northern Dynasties", the Ashina clan was a component of the Xiongnu confederation, but this connection is disputed, and according to the "Book of Sui" and the "Tongdian", they were "mixed nomads" () from Pingliang. The Ashina and Tiele may have been separate ethnic groups who mixed with the Xiongnu. Indeed, Chinese sources link many nomadic peoples ("hu"; see "Wu Hu") on their northern borders to the Xiongnu, just as Greco-Roman historiographers called Avars and Huns "Scythians". The Greek cognate of "Tourkia" () was used by the Byzantine emperor and scholar Constantine VII Porphyrogenitus in his book "De Administrando Imperio", though in his use, "Turks" always referred to Magyars. Such archaizing was a common literary "topos", and implied similar geographic origins and nomadic lifestyle but not direct filiation. Some Uyghurs claimed descent from the Xiongnu (according to Chinese history "Weishu", the founder of the Uyghur Khaganate was descended from a Xiongnu ruler), but many contemporary scholars do not consider the modern Uyghurs to be of direct linear descent from the old Uyghur Khaganate because modern Uyghur language and Old Uyghur languages are different. Rather, they consider them to be descendants of a number of people, one of them the ancient Uyghurs.