After the Battle of Guandu, Cao Cao's unification of the north was unstoppable. In the ninth year of the Eastern Han Dynasty, (204 AD), Cao Cao attacked the city of Yicheng, yuan Shao's young son Yuan Shangbei fled to Youzhou, and defected to his second brother Youzhou to assassinate Shi Yuan Xi, and Cao Cao won Jizhou. Before Cao Cao could continue his conquests, Yuan Xi and Yuan Shang lost all their territory due to the rebellion of his subordinates, and had to go north to Wuhuan. Cao Cao then easily regained Youzhou and basically unified the north.
When Cao Cao prepared the sword guide fang, he would dominate the world! However, he suddenly decided to lead his army to the north to conquer Wuhuan. This expedition to Wuhuan gave Sun Quan Liu Bei the opportunity to develop in the south, so why did Cao Cao do this?
At that time, most of Cao Cao's men opposed the expedition to Wuhuan, first of all, they believed that the expedition to Wuhuan would require crossing hundreds of miles of deserted land. For marching and fighting, such a long journey is a very taboo thing. Moreover, although the remnants of Yuan Shang and other forces were no longer worried, the hundred-footed insects were dead but not stiff, and coupled with their collusion with Wu Huan, a powerful foreign force, attacking them would definitely hurt their bones.
Secondly, Wuhuan is located in a remote area, and once our army goes on an expedition, Liu Bei will definitely encourage Liu Biao to take the opportunity to sneak into Xuchang.
Just as Cao Cao hesitated, Guo Jia, Cao Cao's first strategist, said, "I think it is necessary to fight Wuhuan, and I am sure to win the battle." First, although Wuhuan is far away, it is precisely because they are far away that they are defenseless, and they will not think that we will attack them, and if we are unexpected and suddenly attack, we will definitely be able to catch them off guard. Second, the wolf ambitions of the remnants of Yuan Shao's forces, if we take advantage of our marching south and unite with Wuhuan to attack our rear, then we will be attacked by the enemy. Third, And Liu Biao is just a guy with rhetoric, he has a very high self-esteem, and he will certainly not listen to Liu Bei's opinions. ”
When Cao Cao heard Guo Jia say this, he really felt that it was very reasonable. Moreover, the Yuan family in the north has always been his biggest enemy, and in order to consolidate his rule in the north, it is necessary to completely destroy the Yuan family, so the expedition to Wuhuan is very necessary. Through the use of force to deter, Wu Huan certainly did not dare to covet the Central Plains again.
In fact, there was another reason that made Cao Cao very impressed, that is, the cavalry in the north. Since ancient times, the nomadic peoples in the north have been rich in horses, and it was too tempting for Cao Cao to build a group of cavalry with excellent horses. There is a saying that "the three counties of Wuhuan are the world's famous horses", Cao Cao's expedition to Wuhuan not only needed to obtain these excellent warhorses, but also needed those Wuhuan young adults who could fight well on horseback all year round. These high-quality resources obtained will certainly make themselves play a huge role in unifying the world in the future.
As the saying goes: population is the first productive force. At the end of the Eastern Han Dynasty, after the turbulent decades of the Yellow Turban Rebellion and the division of the princes, the population has been reduced by a lot, whether it is young and middle-aged people who can fight on the front line, or peasants who can supply farmland in the rear, they need a lot of replenishment, and after the capture of Wuhuan, the more than 100,000 Han households and more than 10,000 Wuhuan people who were previously plundered by Wuhuan can move south to the area south of the Great Wall and be organized as subjects of the Han Dynasty. This large number of people gave Cao Cao a great logistical support.
Moreover, he has just unified the north, and many situations are not very stable. And sun quan and others in the south are guarding the natural dangers of the Yangtze River, and there are high-quality water troops stationed, it is not so easy to rush to attack themselves, it is better to consolidate the north first, do a good job in logistics, and then take the opportunity to train a water division, and then it is better to take it in one fell swoop!
It turned out that Cao Cao's expedition to Wuhuan was indeed correct, just as Guo Jia had said. In 207 AD, Cao Cao made an expedition to Wuhuan, and the king of Wuhuan was unprepared, until Cao Cao's army was only more than 200 miles away from him, he woke up like a dream, and in a hurry to fight, he was defeated and killed by Cao Cao, and Yuan Shangyuan Xi had to leave Liaodong and defect to Gongsun Kang. And Liu Bei persuaded Liu Biao to sneak up on Xuchang, and as Guo Jia expected, Liu Biao did not agree, and when Cao Cao returned triumphantly from Wuhuan, Liu Biao regretted it.
Since then, Cao Cao has completely solved the external troubles and consolidated the north, and all the benefits mentioned above have been obtained by Cao Cao, and the situation is very good.
Soon after, Cao Cao was well prepared and marched south to attack Sun Quan Liu Bei, but was defeated at Chibi. In such a well-prepared situation, Cao Cao still had no success, not to mention that he was not ready at that time, if he had rushed south that year, maybe his hometown would have been gone.