Wu Kingdom (229-280), one of the Three Kingdoms, was a regime established by Sun Quan in southeastern China, and the Kingdom’s name was Wu. Wu occupies a region along the southeast coast and is an economically developed area. Because it is regarded to be in the name position as Wei and Shu, together with the fact on ruling the eastern region, it is also called Eastern Wu. The Wu Kingdom is located on the seaside. Thanks to its geographical advantages, Wu vigorously develops maritime economy and trade. This economic development makes the Kingdom and its people rich. At the same time, Wu also developed the shipbuilding industry and cultivated military power. Wu soldiers are good at naval warfare. The largest of Wu’s warships are 5-storey-high and can accommodate 3,000 soldiers. The Battle of the Red Cliff was a battle in which Sun Quan appointed Zhou Yu as the chief commander, commanding 30,000 soldiers in an alliance with Liu Bei, and subsequently defeated Cao Cao’s 200,000-man strong army.