In the twenty-third year of Jian'an (218), Cao Cao sent Cao Ren to crusade against Guan Yu at the same time as the Battle of Hanzhong, but Hou Yin of Wancheng in the rear rebelled, and Cao Ren turned to quell the rebellion. The following year, Guan Yu took the initiative to send troops to surround Cao Ren in Fancheng, and in order to rescue Cao Ren, Cao Cao sent Yu Ban and others to support, but Guan Yu had the upper hand instead.

【Pacifying the Houyin Rebellion】

After the outbreak of the Battle of Hanzhong, Cao Cao should have sent the general Cao Ren to lead a large army in Fancheng out of the need to contain Liu Bei, preparing to crusade against Guan Yu who was guarding Jingzhou.

However, Cao Ren had not yet sent troops, and the Nanyang area in the rear was overwhelmed, under the leadership of Wancheng defenders Hou Yin, Wei Kai and others, Cao Ren had to turn around and put down the rebellion first.

According to the "Biography of the Sages of the Chu State", after Hou Yin launched a rebellion, he wanted to capture Dongligon as a hostage. Ying Yu, who was the county gong cao at that time, took advantage of the chaos in the whole city to escort the Taishou and fled out of the city. When Hou Yin found out, he immediately sent cavalry to chase them down, and caught up with Ying Yu and Dongligon ten miles away from the city. At that time, the rebels saw that the two had no intention of stopping, so they took arrows and shot them at Taishou Dongligon, and the arrows rained down. Ying Yu saw that Taishou's life was in danger, so he stepped forward and used his body to block the arrows for Taishou, and he was hit by seven arrows, but he stood still.

He held his breath and angrily reprimanded the pursuing rebel soldiers: "Hou Yin is rampant and cunning, rebelling for selfishness and becoming a rebel, and now Cao Gong's army is coming soon, and he will be killed and wiped out the Nine Clans." I have always believed that you are good people who have never had a heart for evil, and now you should think about how to abandon evil and turn to good, and why should you obey his commands? I replaced Taishou with my own body life, and now I have been hit hard, and if I can save Taishou with one death, even if I die, there will be no resentment. After speaking, he looked up to the sky and cried, with blood and tears. When the rebels saw that he was loyal and strong, they spared Dongligon's life and captured him. Soon after the rebels left, Ying Yu's life came to an end.

According to the "Biography of Cao Xuan", the officials and people of Nanyang suffered from forced labor at that time, so Hou Yin, the general of Wancheng, captured the Taishou Dongligon (Dongli Zheng) and rebelled with other officials, and they united with Guan Yu outside. Gongcao Zongziqing said to Hou Yin: "You conform to the will of the people and rise up great things, and everyone near and far hopes for you." Now that you have caught the county guard, it is a disobedient act and no benefit, why don't you let him go! Hou Yin listened to Zong Ziqing's words. Zong Ziqing then crossed the city wall at night and followed Taishou to gather the people who did not participate in the rebellion to surround Hou Yin. It just so happened that Cao Ren's army also arrived, so they united to attack Hou Yin and finally wiped him out.

In the process of quelling the Hou Yin Rebellion, Pang De and other generals also came to support Cao Ren at that time, and in the twenty-fourth year of Jian'an (219), Cao Ren broke through Wancheng, beheaded Hou Yin and Wei Kai and slaughtered the city, Cao Cao worshiped Cao Ren as the general of Zhengnan, and Cao Ren returned to Fancheng to garrison after quelling the Wancheng Rebellion.

【Guan Yu is coming】

In the twenty-fourth year of Jian'an (219), Liu Bei pacified Hanzhong, sealed Guan Yu as a former general, and guarded Jingzhou. In the same year (Note 1), Guan Yu took the initiative to send troops north to attack Cao Ren, but Cao Ren was defeated by Guan Yu and surrounded by him in Fancheng.

In history, Cao Ren actually succumbed to a disadvantage in the battle with Guan Yu, which was actually very undeserved.

During the Battle of Hanzhong, the reason why Cao Cao sent Cao Ren to crusade against Guan Yu at this time was to share the pressure of Cao's army in Hanzhong, and on the other hand, it may be related to the rebellion of Jin Yi and Geng Ji in Xuchang, and finally because the three counties controlled by Guan Yu at that time were relatively weak and could be fought.

Since borrowing Jingzhou, although Liu Bei's power has developed rapidly, but the power in Jingzhou is generally weakening, at the beginning of Liu Bei's borrowing of Jiangling, he has Zhuge Liang, Pang Tong, Wu Guan Yu, Zhang Fei, Zhao Yun, Huang Zhong, Wei Yan, occupied a part of Nanjun and Jiangxia County, and almost all of Jingzhou's territory in Jingnan four counties, this is the peak period of Liu Bei's power in Jingzhou, after the sixteenth year of Jian'an (211) Liu Bei entered Shu and took away Pang Tong, Huang Zhong, Wei Yan and others, as well as a considerable part of the army, the following year, Liu Bei and Liu Zhang turned against each other, and he transferred Zhuge Liang, Zhao Yun, Zhang Fei and others into Shu, and took away part of the army again, and the important generals left in Jingzhou at that time were only Guan Yu.

In the twentieth year of Jian'an (215), Guan Yu's power in Jingzhou suffered another major weakening, when Sun Quan asked Liu Bei to return to Jingzhou, Liu Bei did not agree, and the two sides almost fought each other, and finally under the pressure of Cao Cao, Liu Bei ceded Jiangxia County, Changsha County, and Guiyang County to Sun Quan, and Guan Yu's power in Jingzhou shrank by almost half.

And when it came to the battle of Hanzhong, Zhuge Liang was already very reluctant to support Liu Bei on the front line in Hanzhong, if there was a war in Jingzhou, it was foreseeable that Guan Yu would be difficult to get any decent support from Yizhou, and Cao Cao had no problem sending Cao Ren to crusade against Guan Yu at this point in time, but this battle did not take place because of the rebellion in Wancheng in the rear.

But since Cao Ren was sent by Cao Cao to crusade against Guan Yu, then the military strength under Cao Ren's command at that time was at least theoretically similar to Guan Yu, even if it was more than Guan Yu's total strength, it was normal, but Cao Ren didn't fight Guan Yu, but was beaten by Guan Yu, what do you call it.

At that time, Guan Yu's total strength was roughly estimated to be about 50,000, and there were at least 30,000 horses to crusade against Xiangfan, and 20,000 people to garrison Jingzhou, after all, the relationship between Sun Quan and Liu Bei was not good at that time, and Lü Meng's seizure of the three counties was still vivid, Guan Yu had to take precautions against Sun Quan, Lü Meng and others, and leave enough troops to respond, and no more, Liu Bei's power in Jingzhou was weakened three times, and it was already very good to have 50,000 horses, and it was almost the limit to feed 50,000 troops with the land of the three counties.

In this case, Guan Yu was unable to crusade against Xiangfan with all his strength, and Cao Ren was originally preparing to crusade against Guan Yu, but he was beaten by Guan Yu, and he was still defeated in the defensive battle and still needed support, not to mention it.

However, in order to crusade against Guan Yu, Cao Ren had to make a lot of preparations in the early stage, which required additional conscription, which was forced by the ruler to engage in unpaid labor for civilians, mainly including forced labor and military service, etc., in wartime, forced labor was mainly logistics work, military service was to fight as a soldier, and as a result, Wancheng rebelled because the burden of conscription was too heavy, although Cao Ren pacified the rebellion, but the preparation for the southward crusade against Guan Yu was also greatly disturbed, and he was temporarily unable to go south, that is to say, when Guan Yu was crusading against Cao Ren, Cao Ren was probably not ready to start a war with Guan Yu because of the Wancheng rebellion, which was probably the main reason why Cao Ren still needed support at the beginning due to his disadvantageous position.

In addition, I think this has something to do with the people's hearts at that time, Cao Cao's occupation time in the north of Jingzhou was relatively short, and the control was relatively weak, and Cao Ren in order to crusade against Guan Yu, the burden of the people in that area was very large, and Cao Ren also slaughtered Wancheng later, and Liu Bei, Guan Yu and others had a good reputation and high prestige in Jingzhou itself, and the people's hearts may be biased at this time.

Of course, I have to say that Guan Yu himself is a very good commander, and his military ability is still above Cao Ren, Cao Ren was unlucky, he encountered the Han River soaring, the army was submerged, and Guan Yu had the advantage of the water army, so it is understandable that Cao Ren succumbed to the disadvantage.

Note 1: "Sanfu Decision" once recorded that Guan Yu was strong at that time, but I don't think Guan Yu can be powerful just by relying on the land of the three counties.