Kingdom of Wu was consecutively ruled by four emperors and lasted for 52 years. Although Kingdom of Wu was not the strongest one among the three, it had the longest history.

During the rebellion of Dong Zhuo, Sun Jian joined the allied forces against Dong Zhuo. The military area of his troop was mainly to the south of Huaihe River. After Sun Jian died, his son Sun Ce began to lead the army and gradually expanded his military area to the east of Yangtze River.

In 196, Sun Ce made an alliance with Cao Cao and was conferred 'Wu Hou (vassal)' by Cao Cao. In 201 when Sun Ce died, his younger brother Sun Quan took charge with Zhou Yu's assistance. After Sun Quan's army captured Jingzhou and defeated the Shu army in the Battle of Yiling, Sun Quan proclaimed himself emperor in 229.

Under the rule of Sun Quan, the economy of regions in the east of Yangtze River made notable progress. With the development of economy, the number of counties and towns increased largely. Due to the convenient river transportation in the east of Yangtze River, the shipbuilding industry of Wu was prosperous.

Besides, using the advantage of navigation, Kingdom of Wu established close trade routes with some overseas countries such as Vietnam and Cambodia. Meanwhile, both economical development and international exchange also promoted the cultural development of the South Yangtze River regions which produced a group of well-known economists and scholars.

After Sun Quan died in 252, Kingdom of Wu fell into decline day by day. In 282 when Jin Army captured the capital city of Wu - Jianye (currently Nanjing), the last emperor of Wu surrendered, thus ending the glorious reign of the Kingdom of Wu.