The nine-rank system, also known as the nine-grade controller system, was used to categorize and classify government officials by rank in Imperial China. Their accorded rank signified their status in the government hierarchy and the amount of wages they earned. Created by the politician Chen Qun in the state of Cao Wei during the Three Kingdoms, it was used until the Song dynasty, and similar ranking systems were also present in the Ming dynasty and Qing dynasty.
A similar system was also used in Korea. In Japan, the Twelve Level Cap and Rank System was adopted in 603 AD during the reign of Empress Suiko.
History
thumb|Portrait of a young Qing Dynasty [[Mandarin (bureaucrat)|government official with mandarin square of the seventh rank (Mandarin duck) on the chest.]]
Background
Prior to the nine-rank system, official positions were denoted by their salary paid in or ("bushels") of rice or other grains, used to feed and supply their household staff. For example, during the Han, the highest-ranking officials were classed as wanshi<!--see Chinese units of measurement--> (), meaning countless<!--not literally 10k--> bushels, and were paid 350 of grain per month. The lowest ranking petty subofficials were paid in dou ("pecks"), amounting to less than 100 bushels per year.
The nine-rank system was a reorganization of the Han dynasty practice of recommending noteworthy locals for political office. Since 134 BCE, during the reign of Emperor Wu of Han, the Han court relied mainly on nomination by local magnates and officials as a way of identifying talent, by nominating them under titles such as xiaolian (, "filial and incorruptible") or maocai (, "outstandingly talented").
The nine-rank system was created after the end of the Han in 220 AD when Chen Qun, a court official from the state of Cao Wei, proposed it as a way of organizing the state bureaucracy. It was called the "nine-rank method for recruiting men for office" (Jiǔ pǐn guān rén fǎ; ). During the Song dynasty it became the "system of Nine ranks and impartial judges."
Chen Qun's reform was a way of systematizing the selection of candidates for political appointments in two ways: by creating a common scale of nine ranks to evaluate a person and by appointing controllers () in the court to grade officials on the scale. In practice, not only potential entrants but also existing officials were graded, creating two parallel systems: a "candidacy grade" () and a "service grade" (). The system was ostensibly based on a few criteria: moral probity, administrative ability, and the contributions of the person or his family to the newly created Cao Wei regime. In practice, descent also played an important role, since the service grade of a candidate's father had a bearing on their candidacy grade. Through the changes, the nine-rank system also became more closely aligned with the interests of the powerful official clans who had come to dominate imperial politics since the Cao Wei period. The expanded powers of the appointed controllers in turn meant that the officials who held the post, many of whom came from these clans, could use their powers to promote the interests of their own scions. An example of this intrafamilial transmission of skills is the calligrapher Wang Xizhi, of the Wang clan of Langya that was prominent during the Eastern Jin, whose sons, Wang Ningzhi, Wang Huizhi and Wang Xianzhi, were all famed calligraphers in their own right. The emphasis placed by the nine-rank system on moral attributes such as filial piety also led to the growth of "familial instructions" (), which aimed to transmit moral teachings to children, as a genre of writing in the Jin and subsequent dynasties.