Battle of Red Cliffs is a typical battle of defeating the strong with the weak in the history of China. In 208 AD (13th year of Jian 'an, Emperor Xian of Han Dynasty), Cao Cao led an army of land and water, claiming to be a million, launched the Jingzhou Campaign, and then marched eastward to Sun Quan.
Sun Quan and Liu Bei formed a coalition under the command of Zhou Yu, and defeated Cao Jun in Chibi of the Yangtze River (now northwest of chibi city, Hubei Province and northeast of Jiayu). Under the favorable situation, Cao Cao underestimated the enemy's conceit, made mistakes in command and finally lost. Sun Quan and Liu Bei formed an alliance to resist Japan at the critical moment when the strong enemy advanced, and skillfully attacked with fire, eventually defeating the strong with the weak.
This battle laid the foundation for the future separation of Wei, Shu and Wu. Battle of Red Cliffs was also the first large-scale river battle in the Yangtze River basin, and the only war in which Sun, Cao and Liu all sent their main forces to participate.