Kings of the Han dynasty
The kings from other dynasties (, "yìxìng wáng") were mostly remnants of the rebellion against the Qin dynasty. Following the Dazexiang Uprising, many noblemen rose in rebellion. Heirs, pretenders, and warlords called themselves "kings" and claimed sovereignty as continuations of the six states previously suppressed by Qin. Among these, Chu was the most powerful. However, its rightful ruler Huai II was assassinated on the orders of the warlord Xiang Yu and the 18 Kingdoms Xiang had formed rose in rebellion against him. Liu Bang, king of Han, ultimately defeated Chu and established the new Han dynasty. The kings who had sided with him were then permitted to maintain their titles and lands. A few other kingdoms were also formed by Liu Bang for generals and favorites.
Government of the Han dynasty
During the Qin dynasty, the first Qin emperor's legitimacy to rule was ultimately decided by his ability to conquer others. However, by the time of Wang Mang's (r. 9–23 AD) reign, the Mandate of Heaven was considered the only legitimate source of imperial authority. This concept was given greater prominence after the state officially sponsored the worship of Heaven over that of the Five Powers in 31 BC. Moreover, the philosophy of the scholar Dong Zhongshu (179–104 BC), which held that a dynasty's rule on earth was bound to greater cosmological cycles in the universe, was officially sponsored by the Han court from Emperor Wu's (r. 141–87 BC) reign onward. The emperor was expected to behave according to proper ritual, ethics, and morals, lest he incur the wrath of Heaven and bring an end to his reign. He became the highest priest in the land. By performing certain religious rites and rituals, the emperor acted as a sacred link between Heaven and Earth.