During the Three Kingdoms period, there were three decisive battles: after the Battle of Guandu, Cao Cao unified the north; after the Battle of Chibi, Liu Bei and Sun Quan formed a position with Cao Cao; and after the Battle of Yiling, the Three Kingdoms Dingzu was formally established.
The Battle of Yiling took place in the second year of Zhang Wu of the Shu Han Dynasty (222 AD), and Liu Bei, who had just proclaimed himself emperor in Shuzhong, led an army of 50,000 to the east in order to retake Jingzhou, which had been secretly attacked by Sun Quan, to avenge Guan Yu's killing.
As a result, the Eastern Wu general Lu Xun "burned the camp for seven hundred miles" at Yiling, Liu Bei "only spared himself", and Shu Han was seriously injured from then on.
Many people pity Liu Bei, believing that if Liu Bei won the Battle of Yiling, there was a great possibility of pacifying Eastern Wu and even unifying the world.
Let's analyze how likely this is.
First of all, let's take a look at the geographical location of Jingzhou.
Jingzhou was located south of Cao Wei, east of Shu Han, west of Eastern Wu (Jiangdong Headquarters), sandwiched between the Three Kingdoms, and its strategic position was extremely important.
When Lu Su first saw Sun Quan, he proposed that Eastern Wu should "reach as far as the Yangtze River is concerned, and then build an emperor to seek the world." The "Yangtze River" here means that it is best to take Xichuan in the upper reaches of the Yangtze River, or at least Jingzhou in the middle reaches of the Yangtze River.
After the Battle of Chibi, Liu Bei developed at an explosive pace and took most of Jingzhou, causing great survival pressure on Eastern Wu. However, Sun Quan's main enemy at this time was Cao Cao, and he had to unite with Liu Bei, but in Sun Quan's view, not taking Jingzhou was equivalent to building a house and not building a courtyard wall.
Therefore, in order to survive, Sun Quan had to do two things: first, to unite with Cao Wei to resist Shu; second, to devote the strength of the whole country to retake Jingzhou.
Jingzhou was important to Eastern Wu, but it did not mean that without Jingzhou, Eastern Wu could not establish a state. After Eastern Wu lost Jingzhou, there were still in present-day southern Jiangsu, southern Anhui, Zhejiang, Fujian, Jiangxi, Guangdong, Guangxi, and the narrow areas on the north bank of the Yangtze River, most of which were the land of fish and rice, and there was a sufficient supply of grain. In addition, southern Zhejiang, Fujian, Guangdong, and Guangxi are rich in forests and mineral resources, which are enough to ensure the supply of war resources in Eastern Wu.
If Eastern Wu united with Cao Wei and the northern front was safe, it could concentrate its forces against Jingzhou.
Most of the soldiers of Eastern Wu came from the middle and lower reaches of the Yangtze River, and the water was good, so the water army of Eastern Wu was the crown of the Three Kingdoms. Although the Shu Han also had the Yangtze River passing through, the Shu soldiers were not good at water warfare, but were good at mountain warfare. The Jingzhou water network is longitudinal, the Yangtze River crosses the north of Jingzhou, and there is a confluence of Han Water, especially in the north of Jingzhou, which is now Hubei Province, with flat terrain, many rivers and lakes, which is obviously more favorable to Wu Bing than to Shu Bing.
Let's talk about Liu Bei's Shu Han. If Shu Han retakes Jingzhou, it will not mean that everything will be fine, and it is likely to fall into great trouble.
The area of Shu Han is not small, about one million square kilometers, but Hanzhong in the north of Shu Han is not a major grain producing county, and the grain production area of Shu Han is mainly concentrated in the Sichuan Basin with an area of about 260,000 square kilometers. In the southern part of the Shu Han Dynasty, that is, in the south of the South, although the war resources were abundant, such as cattle, war horses, salt, iron, and forests, the Shu Han did not directly control the south central.
After Shu Han recaptured Jingzhou, it was bound to face a strong attack from Eastern Wu, and Cao Wei would also support Eastern Wu from the northern front and create trouble for Shu Han Jingzhou. In order to keep Jingzhou, Shu Han had to station a large number of troops in Jingzhou, which meant that Liu Bei had to transfer troops and grain from Shu Han's headquarters to continuously support Jingzhou.
It should be known that Liu Bei was a foreign ruler to Shu Han, and his cronies were all outsiders to the Shu people; Liu Bei and Zhuge Liang's strict rule of law in Shuzhong had already aroused the dissatisfaction of the Xichuan landlord class, and if Liu Bei transferred Xichuan's military food again, it was bound to further damage the interests of the Xichuan landlord class, and they would inevitably erupt into various forms of resistance, causing serious harm to Liu Bei's clique's rule in Shu Han.
Once the Xichuan rebellion occurred, most of the southern central departments would also respond with troops, and The Powerful Yongmin of Yizhou County (Yunnan, shu Han Jianxing changed its name to Jianning County in the third year), as well as Mu Ke Taishou Zhu Bao, Yue Weiyi Wang Gao Ding, and Nan Wang Meng Yue, these people were not good stubble.
Let's talk about Cao Wei. Although Cao Pi's strategic ability was not as good as that of his father Cao Cao, he would not sit idly by and watch Liu Bei swallow Eastern Wu, and would inevitably unite with Wu to resist Shu.
How did Cao Wei help Eastern Wu? Two things could be done: first, Cao Wei would increase his troops in Xiangyang and, if necessary, attack Jingzhou controlled by Shu Han, Wei would attack the northern part of Jingzhou, and Wu would attack the eastern and southern parts of Jingzhou; second, Cao Wei would attack Hanzhong.
Hanzhong was the northern gateway of the Shu Han Dynasty, and the disastrous consequences of shu Han's loss of Hanzhong were the same as those of Eastern Wu in losing Jingzhou. When Cao Cao occupied Hanzhong, Liu Bei was extremely frightened, and the Shu people were shocked every day. When Liu Bei was fighting in Hanzhong, the front line was not enough, so Zhuge Liang sent troops, Zhuge Liang asked Yang Hong, Yang Hong said very clearly: "Hanzhong, Yizhou throat, the chance of survival, if there is no Hanzhong, there is no Shu. Why should there be any doubt about the calamity of this family? ”
Wei soldiers attacking Hanzhong may not necessarily take Hanzhong, but at least they can contain a large number of Shu Han troops. For the Shu Han, losing Jingzhou is not necessarily the disaster of national destruction, it is not a big deal to retreat to the White Emperor City west of the Three Gorges, and it is also possible to retreat to Eastern Wu according to the Yangtze River, but if Hanzhong is lost, Shu Han will not be far from the fall of the country.
Even if Hanzhong was not lost, Shu Han would inevitably have to increase its troops to defend, and in this case, Shu Han, who had limited national strength, would inevitably have to make a painful choice between defending Jingzhou or Defending Hanzhong.
Of course, whether Cao Wei would continue to march to Xichuan after occupying Hanzhong also depended on the situation on the eastern front. If Eastern Wu had captured most of Jingzhou before Cao Wei, Cao Wei might have maintained the strategic pattern of the Three Kingdoms, stopped attacking Shu, and instead attacked Eastern Wu.
In any case, at this time, the national strength of the Shu Han Dynasty (including army, manpower, food, and economy) would be consumed by most of it, and it was still very likely that Jingzhou would eventually be lost.
Some people may ask: Is Cao Wei capable of fighting on both the Jingzhou and Hanzhong fronts? Of course, in the Three Kingdoms of Wei shu wu, the state of Wei had the largest territory, the largest population, and the strongest strength.
For example, the population, in the official history, says that the population of Cao Wei is more than 4 million, in fact, this is only the registered population, and the population of Cao Wei is estimated to be about 10 million. Therefore, Cao Wei had enough capital to fight a war of attrition with Shu Han and Eastern Wu.
Therefore, even if Liu Bei won the Battle of Yiling and recaptured Jingzhou, due to the weak comprehensive national strength of the Shu Han Dynasty, it was difficult for him to bear the huge price to pay for controlling Jingzhou.
Therefore, Jingzhou is a hot potato, and Liu Bei hastily launched the Battle of Yiling, but he was really blinded by the hot blood, and the gain was not worth the loss.