In October of the second year of Jian'an (197), Cao Cao once again sent troops to attack Zhang Xiu. At that time, Liu Biao's general Deng Ji occupied Huyang, Cao Cao captured Huyang, captured Deng Ji alive and then captured Wuyin in one fell swoop. But Cao Cao still failed to completely defeat Zhang Xiu in the end, occupy Wancheng, and avenge the murder of his son.

In the first month of the third year of Jian'an (198), Cao Cao returned to Xudu, and soon Cao Cao launched the third war against Zhang Xiu.

At that time, Xun You followed Cao Cao to conquer Zhang Xiu and said to him: "Zhang Xiu and Liu Biao help each other and are powerful, but Zhang Xiu is a mobile army, and food must be supplied by Liu Biao, and when Liu Biao is unable to supply him, the two sides are bound to diverge." We might as well pause our march and wait, so that we can tempt us to come; If they rush to attack, they are bound to rescue each other. ”

Xun You's suggestion was very reasonable, but unfortunately Cao Cao didn't listen, and he marched directly to Sui County and fought with Zhang Xiu. Zhang Xiu was in a hurry, Liu Biao really came to the rescue, and under the joint attack of Liu Biao and Zhang Xiu, Cao Cao's army was unfavorable.

Cao Cao regretfully said to Xun You: "It's all caused by not listening to your advice!" Immediately, the surprise soldiers were set up to fight again and defeated Zhang Xiu.

In March of the same year, Cao Cao surrounded Zhang Xiu in Sui County. But later Yuan Shao's subordinates brought the news that Tian Feng asked Yuan Shao to sneak attack Xuchang to seize the Son of Heaven, and when Cao Cao learned about it, he immediately gave up the siege of Zhang Xiu and chose to withdraw to Xuchang.

But at this time, the reinforcements sent by Liu Biao cut off the back route of Cao's army. Cao Cao retreated, Zhang Xiu led the troops to chase after him, and Cao's army could not move forward, so they formed a company camp and were able to advance slowly. Cao Cao wrote to Xun Yu at this time, saying: "The thief army is chasing our army, although we can only walk a few miles a day, but I have calculated that when I arrive in Anzhong County, I will definitely defeat Zhang Xiu."

When they arrived in Anzhong County, Zhang Xiu and Liu Biao's combined forces were guarding in dangerous places, and Cao's army was attacked before and after, Cao Cao sent people to dig a tunnel in a dangerous place by taking advantage of the darkness, smuggling all the baggage materials over, and setting up ambushes. At this time, it was already dawn, and Liu Biao and Zhang Xiu's troops thought that Cao Cao had fled, and the whole army pursued them. Cao Cao sent infantry and cavalry to attack on both sides and defeated the enemy.

In July, Cao Cao returned to Xudu. Xun Yu asked Cao Cao: "Before the war, you expected that you would definitely defeat the thieves, what is the basis?" Cao Cao replied: "The enemy has prevented my troops from returning, and they have fought against me, and I know from this that I will win." In the pursuit, the generals of Zhang Xiu and Liu Biaojun thought that Cao Cao had returned to their hearts, but Cao Cao took advantage of their hearts and did the opposite, successfully luring him into a trap and breaking the enemy army.

But what is unexpected is that after Zhang Xiu was defeated by Cao Cao, he actually organized a second attack and successfully defeated Cao Cao's rear army.

It turned out that as early as when Zhang Xiu pursued Cao Cao for the first time, Zhang Xiu's strategist Jia Xu once said to Zhang Xiu: "If you can't chase, you will be defeated." Zhang Xiu didn't listen, marched into pursuit, and returned defeated. Jia Xu said to Zhang Xiu again: "Hurry up and chase them, and you will win if you fight again."

Zhang Xiu excused himself and said: "I didn't listen to you, I just got to this point, and now I have been defeated, why do you want to chase after you?" Jia Xu said: "There is no definite pattern in the use of troops, and it will certainly be advantageous to march in a hurry." Zhang Xiu believed this, and immediately gathered the scattered soldiers and quickly pursued, fought with Cao's army, and returned victoriously.

So Zhang Xiu asked Jia Xu: "I chased the defeated army with elite soldiers, and you said that it would fail; After retreating, use the defeated army to pursue the newly won soldier, and you say that you will win. The results are as you say, so why did everything you expected come true, contrary to normal practice? ”

Jia Xu said calmly: "This is easy to explain. General, although you are good at using soldiers, you are not Cao Gong's opponent. Although the Cao army began to retreat, Cao Gong must have personally pressed the formation, although the chasing soldiers were elite, since the generals were not opponents, the other party's soldiers were also stronger, so they knew that the chasing soldiers would be defeated. Where the Cao army did not make a mistake in attacking the general, the strength did not decline but retreated, it must have been a change in their country; Having defeated the generals, they must travel lightly and quickly, even if a few generals are left behind, although these generals are brave, they are no longer the general's opponents, so although you can use the defeated army to pursue, you can win. Zhang Xiu expressed his admiration.

Cao Cao in the Jian'an period three crusade against Zhang Xiu, did not make significant progress, on the whole and Zhang Xiu won and lost, took a lot of advantages, but also suffered a lot of losses, because Cao Cao could not gnaw Zhang Xiu's hard bone for a long time, so he finally began to turn his attention to Lu Bu, Yuan Shu and others.

In history, Cao Cao's group crusaded against Zhang Xiu four times in two years, three of which Cao Cao personally led the army, although the record was not large, but some of the generals played very well, such as Yu Ban and Li Tong.

During the first crusade against Nanyang, Cao Cao was very embarrassed due to Zhang Xiu's betrayal. At that time, Cao Cao's subordinate armies were in chaos, and only Captain Pingyu reorganized his troops and withdrew in an orderly manner. On the way, Yu Ban saw Cao Cao's Qingzhou army looting the people, so he counted their crimes and sent troops to attack. After the Qingzhou soldiers fled, they went to complain to Cao Cao. But after Yu Ban arrived, he set up camp first and did not immediately go to see Cao Cao. Someone said to the ban: "Qingzhou soldiers have already gone to sue you first, you should go and explain to Cao Gong quickly." ”

Yu Ban said: "Now the enemy is behind, he will arrive at any time, how can you meet the enemy if you don't prepare first!" And Cao Gong is wise, how can he make false accusations at will! So he calmly dug a trench and set up a camp before he entered to meet Cao Cao and report the whole situation. Cao Cao was very happy, and said to the ban: "The defeat of Nanyang, even I am embarrassed, the general can straighten out his team in the chaos, quell the riot, consolidate the camp, and have unshakable integrity, even if it is an ancient famous general, it will not be better than you!" So he accumulated the exploits before and after the ban, and was named the Marquis of Yishou Pavilion.

Later, Cao Cao crusaded against Zhang Xiu again, because Liu Biao sent people to support, Cao Cao's army fell into a bitter battle, at this time Li Tong came to help Cao Cao with his soldiers overnight, supplemented Cao Cao's soldiers so that Cao Cao could fight again, Li Tong also as a vanguard, turned back to attack Zhang Xiu and broke it. Later, because of this, Li Tong was relocated to the general.

Cao Cao has been fighting Zhang Xiu for a long time, and he has not been able to make contributions. The first thing to investigate is that Cao Cao did a lot of "good things" when he first crusaded against Zhang Xiu, which caused Zhang Xiu to surrender and rebel, and he was also careless; The second is because Zhang Xiu and Liu Biao are united, although Zhang Xiu's force is strong, he is a rootless army after all, and after Liu Biao helps, Zhang Xiu is short of food, Liu Biao is short of generals, the two are simply a perfect combination, and objectively add a lot of difficulty to Cao Cao's crusade against Zhang Xiu; The third is that Cao Cao failed to follow Xun You's strategy to divide the relationship between Zhang Xiu and Liu Biao first, but instead put too much pressure on the two and forced them to unite more closely; The fourth is embroidered with Jia Xu's help, Jia Xu used the trick twice in the three battles in Wancheng, and Cao Cao suffered a big loss.

But the world is impermanent, and later Zhang Xiu actually surrendered without a fight, allowing Cao Cao to get Nanyang for nothing.