Kings of the Han dynasty

The yixing wang represented an obvious threat to the Han empire, and Liu Bang and his successors suppressed them as quickly as was practical: they had disappeared by 157 BC.

For this reason, the title is also translated as "prince" when referring to later kings of the dynasty, to reflect both their link to the ruling house and the vestigial nature of the former vassal kingdoms.

Although nominally under the rule of the Han, these kings were de facto independent and held considerable power within their territories, which could span several prefectures.

As he was dying, the emperor ordered his ministers to swear an oath that only members of the royal house of Liu would be created as kings thenceforth.

The "kings of the same surname" (Chinese: 同姓王; pinyin: tóngxìng wáng) were members of the House of Liu, sons, brothers, or descendants of the Han emperors.

After the Rebellion of the Seven Princes, Emperor Wu reformed the principalities, reducing them to single prefectures and granting superior authority to prime ministers appointed by the central government.

The power to nominate the Crown Prince lay with the throne, although the Emperor generally had to obtain the advice or consent of his high ministers.