In 221 AD, Northern Wei Cao Pi forced Emperor Xian of Han to abdicate, Cao Pi was called emperor, Cao Pi was called emperor soon after Cao Pi was called emperor, Liu Bei also called him emperor, he took Chengdu as the capital, the state name was "Han", and the year was Zhang Wu, that is, the first year of Zhang Wu.
There are at least several reasons why Liu Bei became emperor.
First of all, Liu Bei did lay a huge sphere of influence earlier, and had enough strength to become emperor. After the Battle of Chibi, Liu Bei occupied Jingzhou, laying a solid foundation for his three-part world. Later, he brought Yizhou from Sichuan to the west, and the vast areas of southwest China, as well as Gansu and Hunan, belonged to Liu Bei. Not to mention that Guan Yu later seized a large area of land when he was "threatening China". Even the mighty Cao Cao was defeated by the Shu army. How can you say that such a Liu Bei should not be called emperor?
Second, Cao Pi of Northern Wei forced Emperor Xian of Han to retire to him and changed the name of the country to the State of Wei. In this way, the Han Dynasty that Liu Bei wanted to help perished at the hands of Emperor Xian of Han, and the flag that Liu Bei had been holding was also flawed. Therefore, the ministers quickly recommended Liu Bei as emperor, because this would not only be able to compete with the Northern Wei and thus continue the world of the Han Dynasty; second, Liu Bei's title of emperor was very beneficial to those old ministers who had worked hard for many years, because in this way they became the founding heroes.
The third is Liu Bei's personal thoughts. When Liu Bei was young, he said that he must take the imperial car in the future, and when he grew up, he had been a lord and prince for many years, so that he could not have no desire for power, and it was impossible that he did not want to be an emperor. When he saw Cao Pi claim the title of emperor, he was jealous and went crazy, so it was only a matter of time before Liu Bei called himself emperor.
Liu Bei's emperor era
In 220 AD, Cao Cao died and Cao Pi officially took power. Soon after, he declared himself emperor, and also announced the demise of the Eastern Han Dynasty, and the Three Kingdoms were officially established. In 221, Liu Bei also chose to be emperor and established the State of Shu. After decades of hard work, Liu Bei finally had his own residence, occupying parts of Xichuan and Jingzhou, and also had his own side of the land. But with Guan Yu's defeat, Jingzhou was lost. When Cao Pi was proclaimed emperor, Liu Bei was already very old in this situation, and he proposed the emperor's Zen throne. Only he is qualified to be emperor, and he must also be emperor. Otherwise, it will declare the demise of the Han Dynasty, which will make the orthodox people of the Han Dynasty more unstable and will also put them in a situation of anti-thieves. In fact, Liu Bei had his own views on the emperor.
First of all, he had this qualification; after Liu Bei had always claimed to be the King of Zhongshan Jing, if Liu Xie gave the throne to Cao Pi, as the only clan in the Han Dynasty that still had the ability to compete for the world, Liu Bei would have to stand up and declare that the Han Dynasty had not perished, and that Cao Pi was not an orthodox.
Secondly, Jingzhou had been lost, and Liu Bei's crisis was even greater, so he had to appease the internal personnel, and at this time he was already more than sixty years old, and he still had little time to lead the soldiers to fight and fight for the world, and the generals who followed him for so many years had not yet received the rewards they deserved, so he had to be called emperor and give his generals the positions they deserved, otherwise the insiders would not be sure what would happen.
In the end, Liu Bei's claim to the title of emperor was a kind of pressure on Sun Quan, so that Sun Quan had to make a choice between the dilemma, and in 221 AD, Liu Bei finally chose to be called emperor and formally established the Shu Han regime, making the form of the three divisions of the world more obvious.
Liu Bei's heyday
In 221 AD, Liu Bei proclaimed himself emperor in Chengdu and was named Han. The reason why Liu Bei was called emperor was not only political, but also military achievements. At that time, he did have vast land to support his title as emperor, so how much land did Liu Bei have before he became emperor, and how did his territory develop?
Liu Bei was the county magistrate of Pei County near Xuzhou, and when Tao Qian was seriously ill, he ceded Xuzhou to Liu Bei, who had accumulated some experience through Xuzhou in his early years, but before he could settle down, he was taken away by Lü Bu. But on the other hand, it is precisely because of the failure of Xuzhou that Liu Bei will consider going out to find a way out. He cleverly evaded Cao Cao and defected to Liu Biao in Xiangyang, although during this time, Liu Bei did not have territory, but this was a good time for him to accumulate popularity.
Liu Bei himself was in the vicinity of Longzhong, zhuge Liang was invited to lay the software foundation for later development, and the thirteenth year of Jian'an (208 AD) was Liu Bei's year of great limelight. In that year, Cao Cao led the so-called millions of people to divert water from the south to the north, while Liu Bei and Sun Quan joined forces in the south to fight Cao Cao's criminals.
At Chibi, Sun Liu's army defeated Cao's army, Liu Bei claimed that chaos had captured four counties of Jingzhou, Cao Cao and Sun Quan made his troops rise rapidly, at this time, Liu Bei was sitting in Jiangling and the five counties of Jingzhou, in the nineteenth year of Jian'an (214 AD), Liu Bei took over Luocheng under Pang Tong's plan, besieged Chengdu, Liu Zhang was forced to surrender chengdu, Liu Bei also took over the pastoral area of Yizhou, Jian'an twenty-three years (219 AD), Huang Zhong killed Cao Cao's military general Xiahou Yuan, cao Cao took the opportunity to attack Hanzhong.
However, Huang Zhong and Zhao Yun intercepted Cao Cao's grain and grass, and Cao Cao's army was defeated and had to retreat, and so far, Liu Bei had won a major victory for the third time, ascending to the throne of King Of Hanzhong. At that time, Yizhou was the base area of Liu Bei's rear, easy to defend and difficult to attack.
To the north was Hanzhong, which directly attacked Cao Cao's capital; to the east was Jingzhou, which could attack Sun Quan's Eastern Wu. In the northwest, there is the town of Makou, which guards Gansu, while in the west, there is Chengdu, Liu Bei's headquarters. At this time, Liu Bei was in most of Sichuan, Guizhou, Yunnan, and Gansu, and his territory extended to Hunan, arguably surpassing Eastern Wu, but Guan Yu's journey to Maicheng led to the defeat of Jingzhou. Thus, when Liu Bei became emperor, the four counties of Jingzhou were not under the control of shu Han, but most of their power remained.