“Jun” (郡) was the name of first-level administrative regions in the Western Han Empire, and its subordinate regions were named “Xian” (縣). The administrative governor of a Jun was called “Taishou”(太守), and the commander of a Jun’s army was called “Duwei” (都尉). Both of them were appointed by the imperial government. A Duwei’s salary was lower than a Taishou’s, but a Taishou couldn’t intervene in the work of a Duwei.
The Han Empire also had fedual states, and the states had two types. A state which ruler’s title was “King” was called “king-state”. A state which ruler’s title was “Hou” (侯) was called “hou-state”, and its administrative level was equal to a Xian. In the early times of the Western Han Dynasty, many king-states held several Jun and had independent administration, finance and army. Since Han Jing-Emperor ascended the throne, many king-states were weakened or rescinded. In 145 BC, Han Jing-Emperor gave the administrative power of kings to their prime minister who was directly appointed by the imperial goverment, and the commander of a king-state’s army was also appointed by the imperial government. In 127 BC, Han Wu-Emporer enacted a policy to force kings to enfeoff their sons for setting up hou-states. Since then, the territory of a king-state was similar to a Jun and the administrative level of a king-state was equal to a Jun.