In the mountainous areas around Monan, such as Yinshan, there were a large number of trees at that time, and the flat land had a vast area of grassland.

After Maudun succeeded to the throne, he began to expand externally. After the defeat of the king of Donghu, he immediately annexed Lou Fu and Baiyang Henan King (the other part of the Xiongnu, south of the Hetao), and recovered the Xiongnu land seized by Meng Tian and the Han Dynasty (southeast of Guyuan in Ningxia in later generations), Fushi (in the southeast of Yulin, Shaanxi in later generations) and other counties. and plundered Han Zhiyan, Dai and other places. Attacking the Yue clan to the west, Lao Shangdan Yu succeeded to the throne, defeated and killed the king of the Yue clan, forcing the Yue clan to move to the Western Regions. The tribes of Ding Ling, Hun Yu, Qu Chu, Qi Kun, and Xin Li in the north and northwest successively submitted to the Xiongnu. During this period, the Han Dynasty fought large-scale battles with the Xiongnu. In 201 BC, Han* was forced to surrender to the Xiongnu. In the following year, Liu Bangqin, the ancestor of the Han Dynasty, led an army of 320,000 to conquer, and was besieged by more than 400,000 cavalry of the Xiongnu Maodun Shan in Baideng (northeast of Datong, Shanxi in later generations) for seven days and nights. After escaping, the Han Dynasty adopted Liu Jing's suggestion and implemented a "peace policy" against the Xiongnu, marrying the daughter of the Han clan to Shan Yu, and giving a certain amount of property and opening the customs market to allow the people of both sides to trade. Later texts, Emperor Jing also followed the policy of harmony and proximity to recuperate. However, the Xiongnu were still not satisfied, and sent troops to invade the border from time to time.

The heyday of the Xiongnu was from 209 BC to 128 BC, that is, the period of Maodun, Laoshang, and Junchen Sandanyu, which was equivalent to China from the first year of Qin II to the first year of Emperor Wu of the Han Dynasty. During the period of Yizhi Xiandanyu, the national strength was attacked by the Han army and turned from prosperity to decline.

By the time of Emperor Wu of the Han Dynasty, after nearly 70 years of recuperation, the Western Han Dynasty greatly enhanced its economy and national strength, and turned from strategic defense to strategic offensive against the Xiongnu, launching three major wars: the Battle of Henan (also called the Battle of Monan), the Battle of Hexi, and the Battle of Mobei. At this time, it was the reign of Yi Zhi Xiandan.

In the second year of Yuan Shuo (127 BC), Emperor Wu of the Han Dynasty sent Wei Qing to occupy the Hetao area. In 124 BC, Wei Qing and others were sent to defeat the invading 90,000 Hun cavalry. In 121 BC, Huo was sent to seize the rich Hexi Corridor, and the Han general Zhao Xin persuaded the Xiongnu to move the royal court to Mobei to avoid being attacked, and defeat the Han army with geographical advantages and leisure. In 119 BC, Wei and Huo attacked Mobei from east to west. Huo Qu's disease struck the Xiongnu to the later generations of Mongolia in the territory of the wolf Juxu Mountain, Weiqing East Road swept the Xiongnu royal court. King Youxian led more than 40,000 people to surrender to the Han Dynasty, and the Han army captured more than 70,000 people. The period of decline of the Xiongnu State from Yizhi Shan Yu to Hu Han Evil Shan Yu, experienced 18 Shan Yu, from the Yuan Ding period of Emperor Wu of the Han Dynasty to the end of the Zhi Zhishan Yu in the third year of Emperor Jianzhao of the Han Yuan Dynasty (36 BC).

Around 60 B.C., the Xiongnu Xulu Quanqu Shan died, causing internal divisions, and there were five Dan Yu contending for each other, and the melee continued, and finally developed into the mutual attack of Huhan Evil Shan Yu and Zhi Zhi Shan Yu. In 53 B.C., Hu Han Evil Shan was attached to the Han Dynasty and was the Southern Xiongnu. Under the leadership of Zhizhi Danyu, the Northern Xiongnu defeated Dawan, Wusun and other countries, forced all ethnic groups in the Quartet to pay tribute, shocked the Western Regions, and once led the short-lived revival of the Xiongnu, and was finally destroyed by the Han Dynasty expeditionary force.

The Southern Xiongnu (48-216 AD) was a regime established by the southern Xiongnu aristocracy. It is relative to the Northern Xiongnu who moved westward.

In the early years of the Eastern Han Dynasty, the Xiongnu located in Mobei became stronger and stronger, Liu Xiu was unable to fight with the Xiongnu, Jianwu twenty-four years (48), the Xiongnu internal turmoil for the throne, the Xiongnu nobles killed each other, Hu Han Evil Shan led the troops to join the Eastern Han Dynasty in the day of the king, and the Xiongnu were divided into the Southern Xiongnu and the Northern Xiongnu again.

The Eastern Han Dynasty government set up the Xiongnu Zhonglang to supervise and give the attached Southern Xiongnu a certain amount of grain, silk and other materials every year, and Nandan Yu assisted the Eastern Han Dynasty government to jointly resist the invasion of the Northern Xiongnu, which greatly promoted the integration between ethnic groups.

In the middle and late Eastern Han Dynasty, the power of the Southern Xiongnu increased greatly, because of the complex composition of the tribe, it was difficult to control and control, resulting in internal hiding, many times into the Eastern Han Dynasty to kill officials, and Xianbei many times to join forces to go deep into the interior to raid and plunder, during which several Nandan Yu was killed by his subordinates.

In 187 A.D., there was internal strife in the Southern Xiongnu, at this time it was the Yellow Turban Army uprising, Dong Zhuo "coerced the Son of Heaven to order the princes", and the feudal separatist forces in various places rose together, and the Han Dynasty had no time to take care of the Xiongnu. As a result, the Southern Xiongnu participated in the peasant army's activities to fight local tyrants, and the main areas of activity were north of the Yellow River in Henan Province and the southern part of Shanxi Province. In 195 AD, the Southern Xiongnu participated in the melee of the feudal warlords in the Central Plains, and went down the Yellow River, and Cai Wenji, the daughter of Cai Yong, a scholar of the Eastern Han Dynasty, was taken captive to the Xiongnu during this period. At this time, the Southern Xiongnu had occupied many counties in the Yellow River Valley.

To get back to the point, that is to say, at this time the Northern Xiongnu had been destroyed, and the Southern Xiongnu were attached to the Han Dynasty on the one hand, and on the other hand, they embezzled the Han Dynasty.

At this time, the northern part of the Han Dynasty is all the sphere of influence of the Xianbei tribes, about the Xianbei matter, we will not mention it for the time being, and say that the Southern Xiongnu, the Southern Xiongnu have now occupied a large area of the territory of the Eastern Han Dynasty, including most of the state and the northeast of Liangzhou, that is, Xihai County, but now Xihai County has been recovered by Fu Lin.

Therefore, the Southern Xiongnu are now concentrated in the southern part of Xianbei and the northern part of the Eastern Han Dynasty, that is, in the areas of Wuyuan, Shuofang and Lingzhou in the Great Han Dynasty.

It is also called the Xiongnu Other. From then on, further north, is the Xiongnu royal court, but here and Xianbei border, the southern Xiongnu Xu Pu bone has always been worried about Xianbei's strength. Therefore, he is always thinking about the big territory of the Eastern Han Dynasty.

Just when Fu Lin's two armies were advancing together, the royal court of the Southern Xiongnu also had a 10,000-strong army of soldiers and horses.

In the royal tent of the Southern Xiongnu royal court, Xu Pugu sat on the main seat, he hugged left and right to enjoy, these Han women refined their white and tender skin, looking at the pitiful beauty in their arms, Xu Pugu was immediately ambitious.

At this time, there was a Han man sitting under him, this person was seven feet tall, fat, and looked like a shrewd face, he was none other than Li Su, who had just arrived at the court of the Xiongnu king.

For a while, he sent his house slaves, nominally for Li Dao and Xu Pugu to negotiate, but in fact, it was for him Li Su to seek refuge in the Xiongnu and explore the way, and now he Li Su felt that the time was ripe, so today he came alone with his family, the royal court of the Southern Xiongnu.

Poor Li Dao still thinks that Li Su did not hesitate to risk running for the Huns for the sake of his great cause? At this time, in the king's tent of Xu Pugu, there were some singers dancing, and Xu Pu Gu was looking at the direct flow of Hanlazi.

Li Su, looking at the image of Su Pugu, he likes it from the bottom of his heart, he really likes it, so Li Su said: "King, you are mighty, majestic, and you will definitely be able to achieve hegemony in the future." ”

"Okay, you're very good. I love ...... Hello to you. Su Pugu said in his broken Chinese. Then Su Pugu asked again, "This time, is your information accurate?" Is the northern part of Liangzhou really empty in Fu Lin? As soon as my warriors arrive, it will be of great benefit! ”

"That is, as soon as the king's heavenly soldiers arrive, the enemy chief will be the head. The king can rest assured, he Fu Lin has now done his best to fight a decisive battle with Li Dao, and they will definitely lose both at that time, so how can they have time to care about this. Even if they are still alive by then, as long as the king takes Liangzhou and goes all the way south, Fu Lin and Li Dao will not bow down to their vassals, and Fu Lin's women will be the ones at that time.