Since the Warring States period, the Xiongnu and the Han people in the Central Plains have been sworn enemies. Meng Tian of the State of Qin and Li Mu of the State of Zhao were both generals known for their resistance to the Xiongnu. The Xiongnu were a barbaric nomadic people, and once their strength grew, they went south to plunder the personnel and property of the Han people, and often harassed the border, so Qin Zhao Yan and other countries bordering the Xiongnu built the Great Wall to prevent the Xiongnu from invading from the south, and the people were miserable.
In the unified Han Dynasty, it was even more inseparable from the Xiongnu. When Liu Bang first established the Han Dynasty, the Central Plains had just experienced decades of war and national strength. The outstanding leader of the Xiongnu, Mao Dun Shan Yu, seized this opportunity to invade the Han Dynasty from the south.
At this time, Liu Bang had already eliminated the outstanding founding fathers and military generals Han Xin, Peng Yue and others, and for a time there was no one available, and he could only personally lead his men and horses to Baishan Mountain to break the siege. Liu Bang was eventually defeated by the Xiongnu and was surrounded by the Xiongnu on Mount Baishan for 49 days, and finally gave up his dignity before he and the Xiongnu made peace before breaking the siege.
Because of the humiliation of this country, the Han Dynasty experienced three generations of emperors, accumulated national strength for more than 60 years, and has been related to the Xiongnu to maintain peace. Until the ambitious Han Wudi Emperor Liu Che ascended to the throne, from the time he was a teenager, he fought with the Xiongnu until his two sideburns were white.
During this period, a large number of outstanding famous generals also emerged, but in this decades-long process, there were successful exits, and some failed and captured, but it seems that the Xiongnu treated the captured and surrendered Han Dynasty generals very favorably.
Except for the glory of Wei Qing, Huo Fuyi and others, Wei Lu, Li Ling, Li Xu, Li Guangli did not have so much good luck, they were all captured because of military defeat or forced to be helpless, and took the initiative to surrender to the Xiongnu, but in the days when they were captured, not only did they not suffer humiliation, but they were treated favorably by the Xiongnu, to what extent?
Wei Lu, the first famous general of the Han Dynasty to surrender to the Xiongnu, was once named the king of the Ding Ling Kingdom by the Xiongnu, that is, the leader of a tribe, and was also a feudal official in the Han Dynasty. Li Ling, the grandson of the famous general Li Guang, was also crowned as the king of the Jiankun Kingdom, this kind of "thick favor", these people did not have it in the Han Dynasty, and the nobles who captured the Xiongnu in the Han Dynasty almost did not have a good end, so why did the Xiongnu do this?
Although these Han Dynasty generals superficially surrendered to the Xiongnu, in fact, they were actually forced to helpless, who really wanted to stay in the desolate desert for a lifetime and a group of barbarians for the rest of their lives? Moreover, the Central Plains still had their families and the honors that belonged to their soldiers, so most of them stayed with the Xiongnu, which was just a delaying tactic.
But the Xiongnu needed them, the bitter cold land in northern Saibei, there was no continuous farming, almost nothing could be manufactured, they needed the advanced manufacturing technology of the Han people, and they also needed military talents when fighting the Han, so Li Xu trained troops for the Xiongnu.
When Emperor Wu of Han heard this news, he thought that Li Ling had done it, so he killed his entire family. Li Ling was distraught and sent assassins to kill Li Xu. The Xiongnu Shan Yu later married his daughter to Li Ling, leaving him with no return from then on. Therefore, the preferential treatment policy of the Xiongnu was not out of benevolence, but out of practical necessity.