The last time Liu Bei led his troops to attack Wu was in July of AD 22 1, which was called the Battle of Yiling in history. In AD 2 19, Lv Meng designed an attack on Jingzhou City where Guan Yu was located. Guan Yu was caught off guard and fled to Maicheng, where he was killed by Lv Meng.
After Monroe killed Guan Yu, she cut off Guan Yu's head and went back to show it to Sun Quan. Sun Quan was worried that Liu Bei would attack Wu, so he made an alliance with Cao Pi. Liu Bei, who was far away in Shu, was very sad when he learned of Guan Yu's death.
So in July of 22 1 year, that is, three months after Liu Bei proclaimed himself emperor, Liu Bei revenged his brother Guan Yu and invaded Wu Dong Sun Quan with great fanfare.
Extended data:
The battle of Yiling was caused by Wu's conspiracy to kill his younger brother Guan Yu, and the thief killed Zhang Fei. Liu Bei remembered the friendship of Taoyuan, and did not listen to Zhuge Liang's words. He asked Zhuge Liang to defend Chengdu and personally conquer Dongwu to avenge Guan and Zhang.
Sun Quan was very flustered when he heard about it. He sent someone to make peace and send them back to Jingzhou, but Liu Bei repeatedly refused. Sun Quan had to enlist battle-hardened veterans to play, but he was defeated by Liu Beijun's valiant soldier, and the defeat would be busy.
Huang Zhong was ambushed and killed by an arrow, and Liu Bei vowed to destroy Dongwu. Dongwu suffered a crushing defeat, and the people's hearts fell. When Guan was killed, Zhang's enemies were all killed. Liu Bei will not give up, but will destroy Wu Dong and build a village in Yiling.
At this time, after an argument, Wu Dong appointed Lu Xun as the governor. At first, people refused to accept Lu Xun. Later, they saw Lu Xun's brilliant use of troops and admired him.
Lu Xun saw that Liu Bei's Xiazhai had committed a military taboo and decided to attack by fire. That evening, he went to Liu Beijun to set fire to it. Sure enough, it lit seven hundred miles. Liu Bei was defeated, almost died, and returned to Baidicheng. This is the last battle Liu Bei fought.
Baidu Encyclopedia-The Battle of Yiling