In 219, Sun Quan took advantage of Guan Yu's Northern Expedition to Cao Wei and sent Lü Meng to attack Jingzhou. At the beginning of 220 AD, Guan Yu was defeated and killed. In 221, Liu Bei ascended the throne as emperor in Chengdu and officially established the Shu Han Dynasty. In the same year, Liu Bei led an army to attack Eastern Wu on the pretext of avenging Guan Yu. It is worth noting that before the Outbreak of the Battle of Yiling, Sun Quan sent emissaries to Shu Han to express his attitude of seeking peace.
In the "Romance of the Three Kingdoms, Wu Zhi, Zhuge Jin Biography", it is recorded: "Your Majesty is a relative of Guan Yu, how can he be like the former emperor? Jingzhou size, cooked with the sea? Who should be the first to take the disease? If you look at this number, it is easy to backhand"
Moreover, Zhuge Jin, who had succeeded Lü Mengzhen in defending Jingzhou, also wrote to Liu Bei to persuade him to abandon the attack on Eastern Wu, which meant that the overall situation should be taken as the most important. Of course, neither Sun Quan nor Zhuge Jin could stop Liu Bei's determination to conquer Eastern Wu. As we all know, in the subsequent Battle of Yiling, Liu Bei lost to Lu Xun, a famous general, lost tens of thousands of soldiers and horses, and died of illness in Yong'an White Emperor City in 223 AD.
After this battle, Shu Han was seriously injured and could no longer return to the peak. Therefore, from the perspective of Zhuge Liang, if Liu Bei accepted Sun Quan's claim to peace, he could obviously avoid the decline of Shu Han. However, for the following reasons, Liu Bei still refused to shake hands with Eastern Wu and make peace.
One
First of all, as far as the first point is concerned, if Eastern Wu only sneaks into Jingzhou and lets Guan Yu have a way to survive, Liu Bei may consider dealing with Cao Wei first. In 219 AD, Guan Yu, who was guarding Jingzhou, officially launched the Battle of Xiangfan. In this battle, Guan Yu besieged Cao Ren and achieved the result of flooding the Seventh Army. However, Guan Yu's strength also aroused Sun Quan's vigilance. As a result, Guan Yu was eventually attacked by the two major forces of Cao Cao and Sun Quan, so he suffered a defeat.
For Sun Quan, he had already captured Jingzhou, but he still killed Guan Yu and Guan Ping's father and son. As we all know, as early as the end of the Eastern Han Dynasty, Guan Yu followed Liu Bei to raise troops. In the decades of the Southern Expedition and the Northern War, Guan Yu, Zhang Fei, and Liu Bei have formed a deep friendship, that is, they are not brothers, but like brothers. Compared with Cao Cao and Sun Quan, Liu Bei did not have the help of the clan forces at the beginning of his army. In this context, if Liu Bei did not avenge Guan Yu, it would undoubtedly make Zhang Fei, Zhao Yun and other old subordinates who had followed him for many years chill.
Moreover, in 221 AD, before Liu Bei sent troops, Zhang Fei was killed by his subordinates, and Fan Qiang and Zhang Da, who killed Zhang Fei, fled to Eastern Wu. By this time, because of the superposition of new hatred and old hatred, Liu Bei could no longer turn back, so it was likely that he was aware of Liu Bei's determination, and Zhuge Liang did not directly dissuade him.
Two
Secondly, as far as the second point is concerned, before the outbreak of the Battle of Yiling, although Sun Quan took the initiative to seek peace, he obviously lacked sufficient sincerity. In Luo Guanzhong's Romance of the Three Kingdoms, Sun Quan, fearing the crusade of the Shu Han army, was willing to give up Jingzhou and hand over the murderers of Guan Yu and Zhang Fei. However, this is, after all, a literary work, and there is no relevant record in the canonical history such as the Romance of the Three Kingdoms.
In this regard, in the author's opinion, if Sun Quan really surrendered Jingzhou, Liu Bei really did not have to attack Eastern Wu, that is, he could appease his old subordinates who had followed him for many years. However, Sun Quan had always been eyeing Jingzhou, and now that he had taken it from Guan Yu' hands, he naturally would not give up easily. On this basis, Sun Quan was unwilling to cut off his own interests, and Liu Bei would not give up. In other words, if Liu Bei gave up the conquest of Eastern Wu, it would be difficult to make an account to the Shu Han and even weaken his prestige. From this point of view, the question of the ownership of Jingzhou became a difficult contradiction between Shu Han and Eastern Wu, and if it were not for the heavy blows suffered in the Battle of Yiling, Liu Bei might still try to retake Jingzhou.
Three
Finally, as far as the third point is concerned, Liu Bei is confident of winning the Battle of Yiling. Throughout Liu Bei's life, the first half of his life can be said to be turbulent and displaced, repeatedly defeated, in the process of chasing deer in the Central Plains, Liu Bei was defeated by Lü Bu, Cao Cao and other princes, and lost his foothold, which can be described as very embarrassing. However, starting from the Battle of Chibi in 208 AD, Liu Bei was repeatedly victorious.
In 209, taking advantage of Cao Cao's retreat back to the Central Plains, Liu Bei captured four counties in the south of Jingzhou and finally gained a foothold. In 211, at the invitation of Liu Zhang, Liu Bei led an army into Yizhou. A year later, Liu Bei and Liu Zhang broke up and the Battle of Yizhou officially broke out. In 214, Liu Bei defeated Liu Zhang and captured the land of Yizhou.
In 217 AD, Liu Bei launched the Battle of Hanzhong. Two years later, Liu Bei repelled the mighty Cao Cao and seized the land of Hanzhong. In this regard, in the author's opinion, it is precisely because of the continuous victory that Liu Bei's confidence in defeating Eastern Wu has increased. Further, Liu Bei, who was already somewhat inflated, led an army of 50,000 to attack Sun Quan, most likely to eliminate Eastern Wu in one fell swoop, thus dividing the world with Cao Wei. For the Three Kingdoms of Wei Shu and Wu, Cao Wei was clearly ahead in strength. In this context, whether it was Shu Han or Eastern Wu, it was more difficult to resist Cao Wei alone.
Therefore, Liu Bei wanted to defeat Cao Wei, who replaced the Han Dynasty, and complete the long-cherished wish of Kuangfu Han, then the elimination of Eastern Wu would be an important springboard to achieve this goal. From this point of view, before the outbreak of the Battle of Yiling, since Liu Bei had the intention of destroying the other side, he would not take Sun Quan's initiative to seek peace seriously. Of course, the ideal is very full, the reality is very bone, although the general Lü Meng, who sneaked into Jingzhou, died of illness, but Liu Bei was still defeated by Lu Xun, which caused Shu Han to basically lose the opportunity to dominate the world.