In 219, Liu Bei defeated Cao Cao at the Battle of Hanzhong and established himself king of Hanzhong, after which Liu Bei rewarded his meritorious ministers, and he had Guan Yu, Zhang Fei, Ma Chao, and Huang Zhong ranked the four generals separately, and then he began to arrange for the general To guard Hanzhong. Since Hanzhong was the throat of Shu and was won by Liu Bei after many hardships, his choice to sit in Hanzhong must have been well thought out, and most people at that time thought that Liu Bei would definitely choose Zhang Fei as the Taishou of Hanzhong, and Zhang Fei also felt that this position was his own, but the result was unexpected, when Liu Bei did not appoint Zhang Fei as the Taishou of Hanzhong, but promoted Wei Yan to Hanzhong Taishou, and promoted Wei Yan from the general of Yamen to the general of Zhenyuan, and Zhang Fei was sent by Liu Bei to sit in Langzhong. I have to say that at that time, Liu Bei's decision made many people very confused, and even some people thought that this was a signal that Liu Bei did not value Zhang Fei, so after Liu Bei seized Yizhou, why did he send Zhang Fei to sit in Langzhong instead of Hanzhong? Because Zhang Fei is not important?
In fact, Liu Bei sent Zhang Fei to Langzhong, not because Zhang Fei was not important, but because Zhang Fei was too important, to know that although Langzhong was not as famous as Hanzhong, the strategic significance of this place was very significant, starting from Langzhong, shang could go directly to Hanzhong along the right road, if there was a crisis in Hanzhong war, Zhang Fei could quickly attack, go to Hanzhong to support Wei Yan, to ensure that Hanzhong was not lost, and if he went down the river to the east, Zhang Fei could directly reach Jiangzhou to support the eastern front, enter and exit Jiangzhou to attack Eastern Wu, and retreat to prevent the attack of Eastern Wu. It was for this reason that Liu Bei would let Zhang Fei mobilize a large army from Langzhong before the Eastern Crusade. The most crucial thing is that Langzhong is not far from Chengdu, there is no pass in the middle, if something happens in Chengdu, Zhang Fei can directly lead the army to come to support.
And the most easy to ignore is Liu Bei's wariness of others. It should be known that at that time, Guan Yu was sitting in Jingzhou, Ma Chao was oversaw Linfeng, and Zhang Fei was guarding Langzhong, and the Linfeng where Ma Chao was at that time was in the middle of Guan Yu and Zhang Fei, so that Ma Chao was always under the restrictions of Guan Yu and Zhang Fei, and it was difficult to rebel.
It is a pity that Zhang Fei has a fatal flaw in his personality, doomed to the tragedy of losing the hand of a villain, and at this point, Liu Bei is expected, so Liu Bei has reminded Zhang Fei many times to ask Zhang Fei to be careful, but Zhang Fei did not listen to Liu Bei's words, so that he was secretly attacked and died by his own men, which also made Liu Bei install Zhang Fei in Langzhong without doing anything.
The author believes that compared with Hanzhong, Langzhong's task is heavier, so Liu Bei installed Zhang Fei here, not because Zhang Fei is not important, but because Zhang Fei is too important.