Sadaijin (Minister of the Left) (左大臣)
The Minister of the Left was a government post in the Daijokan (Grand Council of State), the central administrative body of the Imperial Court. The Chinese names were "Safu," "Sajosho," "Sashokoku," "Sabokuya," and "Taifu." The Japanese readings were "Hidari no oimouchi gimi," and "Hidari no otodo." It was equivalent to the official rank of Shonii or Junii (Senior or Junior Second Rank).
As its another name, "Ichi no kami" (the chief administer) indicated, it was like the head of Taikaku (cabinet) that oversaw all functions of Daijokan. As Daijo-daijin (Grand minister of state), which was above Sadaijin in rank, was not a permanent position, it was not appointed in the absence of a qualified person; therefore, in such a case, Sadaijin was the top rank in Daijokan. Daijo-daijin was later regarded as an honorary post, and Sadaijin bacame virtually the supreme leader of Daijokan.
According to "Nihon shoki" (the Chronicles of Japan) and "Shoku Nihongi" (Chronicle of Japan Continued), there were some cases in which the post of Sadaijin also became vacant if there was no one qualified for Daijokan in the early Ritsuryo System. In that case, Udaijin (minister of the right) acted as a substitute.