Battle of the Red Cliff
Cao Cao, who declared himself the Prime Minister, led his troops to attack southern China after uniting the north. At Xinye, he was defeated twice by Liu Bei’s forces but Liu Bei lost Xinye and had to move to Jingzhou. Unfortunately, Liu Biao had died by then and left Jingzhou split between his two sons Liu Qi and Liu Cong. Liu Bei led the civilians of Xinye to Xiangyang, where Liu Cong ruled but Liu Bei was denied entry. Liu Cong later surrendered to Cao Cao, and Liu Bei had no choice but to move to Jiangxia where Liu Qi ruled. On the way, Liu Bei and the civilians were pursued by Cao Cao’s troops and several innocent civilians were killed. Liu Bei and his men managed to reach Jiangxia where he established a strong foothold against Cao Cao’s invasion.

To resist Cao Cao’s invasion, Liu Bei sent Zhuge Liang to persuade Sun Quan in Jiangdong to form an alliance. Zhuge Liang managed to persuade Sun Quan to form an alliance with Liu Bei against Cao Cao and stayed in Jiangdong as a temporary advisor. Sun Quan placed Zhou Yu in command of the forces of Jiangdong (Eastern Wu) to defend against Cao Cao’s invasion. Zhou Yu felt that the talented Zhuge Liang would become a future threat to Eastern Wu and tried several times to kill Zhuge Liang, but failed. In the end, he had no choice but to co-operate with Zhuge Liang for the time being as Cao Cao’s armies were at the border. Cao Cao was defeated at the Battle of the Red Cliff, also called the battle of Chibi, by the combined forces of Liu Bei and Sun Quan and forced to flee back to Jingzhou.