After the Battle of Chibi, Liu Bei took advantage of the confrontation between Zhou Yu and Cao Ren to quickly move south and capture the four southern counties of Jingzhou. Don't look at the four southern counties, which are inconspicuous, they can probably occupy half of jingzhou's territory, and half of them can be used for farming.
Liu Beigang escaped from Chibi's death and picked up such a large piece of land, it is reasonable to say that he should be satisfied. Then why didn't he guard this fertile wilderness and live a down-to-earth life, and had to borrow Nan County from Sun Quan?
Is Liu Bei willing to be in a corner of peace? Since Liu Bei arrived in Jingzhou, in addition to helping Liu Biao guard the north gate of Jingzhou, there has been no improvement in his career. At that time, Liu Bei was already more than half a hundred years old, was this life just over?
Liu Bei was very unwilling, so Xu Shu recommended his good friend Zhuge Liang to him. After Zhuge Liang joined Liu Bei's clique, he offered Longzhong to the pair, so that Liu Bei finally found the goal of struggle, according to Jingzhou, taking Yizhou, and then choosing the time of the Northern Expedition, in an attempt to restore the Han Dynasty.
Soon, Liu Biao died of illness, and the young Liu Chun was succeeded by Jingzhou. Cao Cao, Lu Su, and Zhuge Liang heard the news and invariably focused their attention on Xiangyang. Among them, Cao Cao immediately gathered 150,000 troops to kill Xiangyang; Zhuge Liang suggested that Liu Bei immediately take his place, but Liu Bei did not follow; Lu Su finally arrived and met Liu Bei, who had fled the wilderness.
However, Liu Bei and Zhuge Liang did not abandon the Longzhong plan because of this, but actively allied with Sun Quan to jointly deal with the menacing Cao Cao army. At such a difficult moment, Liu Beishang did not give up the dream in his heart. After occupying the four southern counties of Jingzhou, what reason is there to retire in peace?
Therefore, the capture of the four counties of Jingzhou was only a small step in the middle of Longzhong, where it could provide food and soldiers for Liu Bei's larger military operations. And all this stems from Liu Bei's dream, Wang Ye is not biased.
Since Liu Bei was not willing to be in a corner of Nan County, he had to continue to implement Longzhong's next strategic plan and benefit the state.
Although there was more than one road to Yizhou, Liu Bei could also start from Lingling County and then enter southern Yizhou from Yungui. But, for its part, no one would abandon the convenient waterways and cross mountains thousands of miles long and thousands of meters high. Therefore, the Yangtze River running through Nan County is Liu Bei's best choice. Then, before entering Yizhou, it is necessary to occupy Nan County.
In fact, after the Battle of Chibi, Zhou Yu locked his eyes on Nan County, and after fighting with Cao Ren for a year, he finally included it in the pockets of Eastern Wu. Zhou Yu is very ambitious, and his strategic vision is almost the same as Zhuge Liang's. The capture of Nan Commandery was only the first step, and his next goal was also to take Yizhou, occupy Hanzhong, ally with Ma Chao, and then plot northern expeditions from Nan Commandery to Cao Cao.
Therefore, as long as Zhou Yu lived, it was almost impossible for Liu Bei to borrow Nan County. You see, after Cao Ren retreated, Zhou Yu immediately garrisoned Jiangling. Although Liu Bei was nominally Jingzhou Mu and Sun Quan's brother-in-law, Zhou Yu did not give him more territory because of this, but gave him the public security office on the south bank of the Yangtze River.
Earlier, Zhang Song had already thrown an olive branch to Liu Bei, hoping that Liu Bei would definitely take Yizhou in the west before Cao Cao. However, the public security was very embarrassed, and went upstream to be pulled by Zhou Yu of Jiangling, and down was intercepted by Cheng Pu of Sha Xian. In other words, Liu Bei was trapped in the cage of Eastern Wu.
In order to get out of the predicament, Liu Bei ignored Zhuge Liang's persuasion and personally went to Jingkou to ask Sun Quanneng to entrust Nan County to his own care. At this time, Sun Quan remembered Zhou Yu's plan to cut down Shu, so he deliberately tested Liu Bei, but Liu Bei refused to send troops on the grounds that Liu Zhang was a clan relative.
Zhou Yu saw That Liu Bei had gone to Jingkou, suspecting that Liu Bei was fighting Nan Commandery's idea, and also knew that his real intention of borrowing Nan Commandery was to plot YiZhou. Yizhou, at this moment, is very much like Jingzhou two years ago, whoever acts first may have the upper hand. Unable to hesitate any longer, Zhou Yu immediately wrote an urgent letter to Sun Quan, hoping that Sun Quan would directly detain Liu Bei in Jingkou. However, Sun Quan was undecided, he wanted to detain Liu Bei, but he was jealous of Cao Cao, and at this time Eastern Wu needed allies like Liu Bei, so Liu Bei returned to public security safely.
Zhou Yu saw Liu Bei return and understood that Sun Quan did not have enough confidence in himself. Therefore, he quickly went to Jingkou, personally met Sun Quan, and requested that Xichuan be attacked immediately. Sun Quan thought about it again and again, and finally agreed to Zhou Yu's plan. However, perhaps it was Heavenly Help Liu Bei, just when Zhou Yu was ready to do a big job, but on the way back to Jiangling (Baqiu), he suddenly died of illness, and Eastern Wu's plan to attack Xichuan was stranded.
Soon, Liu Bei ushered in a second good news, and his old friend Lu Su succeeded Zhou Yu. The biggest difference between Lu Su and Zhou Yu was that Zhou Yu believed that Eastern Wu could go it alone, while Lu Su was more in favor of the alliance. Although Zhou Yu is more ambitious, Lu Su is more sober. Although Eastern Wu occupied Nan Commandery, most of Liu Biao's original Jingzhou team defected to Liu Bei. Moreover, the strength of Eastern Wu at that time alone was not enough to cope with the pressure from Shukou and Xiangyang, and then tried to defend Yizhou, which was easy to defend and difficult to attack, which was simply not self-sufficient.
Under the persuasion of Lu Su, Liu Bei was finally able to successfully enter Nan County. Soon after, under the operation of Zhang Song, Liu Bei received an invitation to enter Yizhou in the west. As a result, Liu Bei began to execute the second move of the Longzhong pair, the west to take Yizhou.
After the Battle of Chibi, if the four southern counties of Jingzhou could provide Liu Bei with troops and grain, then Nan County was the passage that helped him enter Yizhou. If only Zhang Song's cooperation, Zhou Yu would not die, and Liu Bei would not be able to enter Xichuan.
Lu Su lent Nan Commandery to Liu Bei, in addition to asking Liu Bei to share the military pressure from Cao Wei Xiangyang for Eastern Wu, but in fact deliberately borrowed the road. Liu Bei successfully took Yizhou and returned it to Nan Commandery; if it did not succeed, the leaderless Jingzhou soldiers would have to defect to their ally Sun Quan in the future.