The system of Three Lords and Nine Ministers

The System of Three Lords and Nine Ministers was a central government organizational structure that emerged in the Qin and Han dynasties (221 B.C. - A.D. 220) in imperial China. The system took shape as early as the Xia Dynasty (c. 2100 B.C. - 1600 B.C.). When a unified feudal country was established by the First Emperor of Qin, the bureaucratic systems of previous states were integrated into a complete System of Three Lords and Nine Ministers for the central government.

The "Three Lords and Nine Ministers" were senior officials in the central government. The "Three Lords" were the Prime Minister, the Grand Marshal, and the Imperial Counsellor, the three most esteemed official positions. Respectively responsible for administration, military affairs, and oversight, they represented the separation of powers in the traditional Chinese political system with administration playing the primary role. The "Nine Ministers" were the heads of functional departments. The number of functional departments – and hence of ministers – was not necessarily nine. The number "nine" suggested a complete set of official posts. This system remained in place during the Jin Dynasty (265-420) and the Southern and Northern dynasties (420-581) until it was replaced with the System of Three Departments and Six Ministries, which Emperor Wendi of the Sui Dynasty (581-618) created based on this old structure.

三公九卿制

三公九卿制是秦漢時期形成的中央政府組織架構，是中國古代封建社會的一種官員制度。三公九卿制早在夏朝就已初具規模。秦朝建立封建統一國家后綜合列國官僚制度，在中央政府建立起了完備的三公九卿制。

“三公九卿”是中央政府高級官員的統稱。“三公”是最尊顯的三個官職的合稱，即掌管行政的丞相、掌管軍事的太尉和負責監察的御史大夫，其代表中國傳統以行政為主導的行政、軍事、監察三權分立政治體制。“九卿”是各職能部門的長官，不一定是九個人或九種官職，意味著其官職完備。這一官員制度一直沿用到兩晉南北朝時期，直至隋文帝在其結構基礎上創設三省六部制，三公九卿制才退出歷史舞臺。