In the early years of the Han Dynasty (206BC-8AD), in order to strengthen his influence, Emperor Gaozu granted many virtually autonomous vassal states to his relatives and a few generals with military merits. Inevitably, over a period of time these vassal states grew powerful. However, when Liu Bang became the emperor, his wife got the power and only assigned those with her family name Lu to important posts. And it aroused great dissatisfaction among Liu's family members.

The kingdoms that were in the hands of vassal-state rulers become a threat to the central government. During the reign of Jingdi, the minister Chao Cuo recommended to weaken the power of vassal-state rulers by eliminating their fiefdoms. And this action led to the Rebellion of the Seven Kingdoms.

In 154BC, the ruler of the Wu State rose up and then other rulers in six states followed suit. It took three months for Emperor Jingdi to quell the rebellion. Later, Emperor Wu continued to weaken the power of the vassal states by eliminating many fiefdoms, restoring central control over the prefectures and counties of the country.