In Ci Hai, the Xiongnu is described as follows: "Xiongnu, as China called it in ancient times, is also called Hu. During the Warring States period, it was active in the areas north of Yan, Zhao and Qin. During the Qin and Han dynasties, Morton Khan unified all ministries and was powerful, ruling the vast areas in the north and south of the desert. At the beginning of the Han Dynasty, the Han Dynasty basically adopted a defense policy. During the period of Emperor Wu of the Han Dynasty, he turned to attack Xiongnu and marched into Mobei many times. Xiongnu suffered a great blow and its power gradually declined. In the second year of Ganlu in Xuan Di (52 BC), Uhaanyehe joined the Han Dynasty and came to Korea the following year. In the following six or seven decades, the economic and cultural exchanges between Han and Xiongnu were frequent. In the 24th year of Jianwu (AD 48), Guangwudi of the Eastern Han Dynasty was divided into two parts. The one attached to the Han Dynasty in the south was called the South Xiongnu, and the one staying in Mobei was called the North Xiongnu. Southern Xiongnu lived in Shuofang, Wuyuan, Yunzhong (in today's Inner Mongolia Autonomous Region) and other counties, and was divided into five parts at the end of the Eastern Han Dynasty. During the Western Jin Dynasty, Zhao, Xia, Beiliang and other countries were successively established. The Northern Xiongnu was defeated by the Eastern Han Dynasty and the Southern Xiongnu when he was emperor, and some of them moved westward. "
The grasslands in the north and south of China desert are the big stage for nomadic activities in northern China. Before the Warring States period, there were clans or tribes such as Hunzhou (sound: Yu Xun), Ghost Fang (sound: Xianyun), Rong and Di. During the Spring and Autumn Period and the Warring States Period, there were wars between them and between them and all ethnic groups in China. Some tribes disappeared, some tribes were annexed by the vassal states of all ethnic groups in China, and some developed and expanded. By the end of the Warring States Period, many clans and tribes in northern China had formed tribal alliances within a certain geographical scope. One of them is the Huns.
At the beginning of the Xiongnu's birth, it was mainly in the Hetao area of the Yellow River in Monan (referring to the east of Helan Mountain, the south of Langshan Mountain and Daqingshan Mountain in Inner Mongolia and Ningxia Hui Autonomous Region and the areas along the Yellow River, collectively referred to as Hetao) and Yinshan area (Langshan Mountain and Daqingshan Mountain in Inner Mongolia). ). According to the biography of Xiongnu in Han Dynasty, there are "lush vegetation and numerous animals", which shows that such geographical conditions are very beneficial to animal husbandry and hunting. Huns used these natural conditions to develop nomadic economy. They "migrated by aquatic plants", "ate animal meat, drank cheese, wore leather clothes, were felted and lived in the cellar", and this description in Hanshu (Biography of Xiongnu) was a true portrayal of the nomadic life of Xiongnu at that time.
The first Khan of Xiongnu was Tou Man Khan. At that time, the center of Xiongnu tribal alliance was Toumancheng (in Guyang area of Wuyuan County, east of Baotou City, Inner Mongolia). During the war in the Central Plains at the end of the Warring States Period, the nobles of Xiongnu slave owners seized the "Henan Land" south of Hetao (now Ikke Zhao Meng area in Inner Mongolia), which led to the border between Qin, Yan and Zhao being restless. In 265 BC, Li Mu, the general of Zhao, defeated the Huns by more than 100,000 yuan. After Qin Shihuang unified the six countries, in 2 15 BC, Meng Tian, a general, led 300,000 troops to fight against the Huns and recover the "land of Henan". In the second year, Gaoque (now northwest of He Lin, Inner Mongolia) and Yangshan (now Wolf Mountain in northwest of He Lin, Inner Mongolia) controlled by Xiongnu were captured. The Huns had to retreat more than 700 miles north. The Qin Dynasty set up counties and counties in the prominent places of Xiongnu, and renovated the Great Wall connecting Qin, Zhao and Yan, starting from Lintao (now Minxian County, Gansu Province) in the west, along the Yellow River north to Hetao, down Yinshan Mountain to Liaodong (now Liaoyang City, Liaoning Province), stretching near Wan Li to prevent Xiongnu from invading again. In 207 BC, the Qin Dynasty was overthrown, Chu and Han contended, and the Central Plains was in chaos. Xiongnu took the opportunity to cross the Great Wall and reoccupy Hetao area and Yinshan area.
In 209 BC, modu chanyu killed his father Tou Man and became Khan himself. In the early Western Han Dynasty, a slave country-Xiongnu Khan was established. The control area starts from Yinshan Mountain in the south, reaches Lake Baikal in the north, reaches Liaohe River in the east and exceeds Conglin Mountain in the west. The establishment of Xiongnu regime ended the dispersed situation of nomadic tribes in northern China. During the reign of Morton Khan, Xiongnu conquered many tribes successively. According to Biography of Xiongnu in Historical Records, it destroyed Donghu, drove away the Yue family (sound: branch), merged Loufan, Aries and King of Henan in the south, served Hunyu, Qushe, Dingling and Qikun in the north, then destroyed the Yue family, and settled Loulan, Wusun and their twenty-six families.