The Revolt of Seven Countries

At the beginning of the Han, Liu Bang named many of his relatives (with the same last name) kings who owned certain lands. This act was meant to help the emperor rule the empire. But during the reins of emperor Wen (Han WenDi), these kings set their own laws, casted their own coins, collected their own taxes and were in opposition to the central government publicly. Han Wendi took some measures, solved the problem but did not cut its root. When emperor Jin (Han JingDi) came to power, the rich kingdom of Wu was very domineering. Jingdi thus took an idea given to him by a high officer and weakened the powers of these kings. BC 154, the king of Wu persuaded the kings of all of the seven kingdoms to a revolt against the central government. Jingdi ordered Zhou Yafu to launch an attack against the revolting army and pacified the revolt of seven countries in three months. After the pacification, Han Jingdi weakened the powers of these kings further.