When did Liu Bei become emperor?

22 1 year, Liu Bei, king of Hanzhong, proclaimed himself emperor in Chengdu. In 220, after Cao Pi proclaimed himself emperor, it was widely rumored in Shu that Liu Xie, the Han emperor, had been killed, so Liu Bei, as an imperial clan, sent out mourning uniforms and worshipped Liu Xie as the filial emperor. Afterwards, Liu Bei's men advised Liu Bei to be emperor, but Liu Bei disagreed. General Zhuge Liang, a military strategist, said that Liu Bei agreed, and it would be a great honor to ask Zhuge Liang, Dr. Xu Ci and Meng Guang, a military strategist, to set etiquette and choose an auspicious day. In the second year of Wei Huang (22 1), on April 6th, Liu Bei proclaimed himself emperor in Chengdu, and he was the Emperor Zhaolie of Han Dynasty and the forerunner of Shu. Because he called for the revival of the Han dynasty, the title was still Han and changed to Zhangwu. Because there is only a corner of Yizhou, it is also called "Han Shu" or "Han Ji". Liu Bei took Zhuge Liang as prime minister and Xu Jing as Stuart. Set up 100 officials, set up ancestral halls and worship ancestors. On May 12, Mrs. Liu Beili became the queen, made her son (A Dou) the crown prince, and married the daughter of Zhang Fei, a sedan chair general, as the crown princess.