Cao Wei

 ( 220 Establishments ) 

Sima Shi deposed Cao Fang in 254, on grounds of planning to stage a rebellion, and replaced him with Cao Mao. In response, Guanqiu Jian and Wen Qin staged a rebellion, but were crushed by Sima Shi in an event that nevertheless took a heavy toll on Sima Shi's health, having undergone eye surgery prior to the insurrection, causing him to die on 23 March 255,(正元二年闰月疾笃，使文帝总统诸军。辛亥，崩于许昌，时年四十八。) Jin Shu, vol.02 but not before handing his power and regency over to his younger brother, Sima Zhao.

In 258, Sima Zhao quelled Zhuge Dan's rebellion, marking an end to what are known as the Three Rebellions in Shouchun. In 260, Cao Mao attempted to seize back state power from Sima Zhao in a coup, but was killed by Cheng Ji, a military officer who was serving under Jia Chong, a subordinate to the Simas. After Cao Mao's death, Cao Huan was enthroned as the fifth ruler of Wei. However, Cao Huan was also a mere figurehead under Sima Zhao's control, much like his predecessor. In 263, Wei armies led by Zhong Hui and Deng Ai conquered Shu. Afterwards, Zhong Hui and former Shu general Jiang Wei grouped and plotted together in order to oust Sima Zhao from power, however, various Wei officials turned against them when it was found out that Jiang Wei had urged Zhong Hui to get rid of these officials before the planned coup. Sima Zhao himself received and finally accepted the nine bestowals and the title Duke of Jin in 263, and was further bestowed with the title King of Jin by Cao Huan in 264, but he died on 6 September 265,(咸熙二年秋八月辛卯，帝崩于露寝，时年五十五。) Jin Shu, vol.02 leaving the final step of usurpation up to his eldest son, Sima Yan.

On 4 February 266, Sima Zhao's son, Sima Yan, forced Cao Huan to abdicate in his favor, replacing Wei with the Jin dynasty on 8 February 266. Cao Huan himself was spared, though, and continued to live until 302, before dying.(年五十八，太安元年崩...) Wei Shi Pu annotation in Sanguozhi, vol. 04. The year corresponds to 14 Feb 302 to 02 Feb 303 in the Julian calendar.

During this time, the minister Chen Qun developed the nine-rank system for civil service nomination, which was adopted by later dynasties until it was superseded by the imperial examination system in the Sui dynasty.

Cao Pi felt that the Han dynasty collapsed because the Governors (州牧) of the various provinces wielded too much power and fell outside the control of the central government. He reduced the role of a Governor to that of an Inspector (刺史), and permitted the Inspectors to administer only civil affairs in their respective provinces, while military affairs were handled by military personnel based in regional offices or in the capital.

Cao Wei society was feudalized and vassalized. When China was divided in the Period of Disunion, south and north were economically and socially dominated by an aristocratic hereditary class enshrined in law, who were exempt from conscript labor, special kinds of taxes, had legal immunities and other privileges. This situation was created by Cao Wei with rigid social stratification backed by law between shu (庶) (commoner) households and shi (士) (noble) households in the Nine ranks system which was created by Cao Wei and enabled hereditary officeholding by the aristocratic magnate families. Magnates took in farming families and war refugees into their fortress villages as ke (客) (private clients) and as buqu (military retainers) who made up their private militias. These magnates were rich landowners and local warlords and their economic and social power only grew at this time. The military retainers stayed own as private agricultural laborers bonded to the magnate families even after war ended. They did not contribute any labor service or taxes to the central government while their magnate lord received 50% or more of their grain harvest. They effectively were bondservants to their lords.