Abstract: This article for the first time recreates the biography of Karl Petrovich von Rüdinger (1753-1821) – a liflyandsky baron, who was the native of Phelinsky uyezd. During 1779-1797 he served in the Land Gentry corps, received the rank of the privy councilor (1797) and the post of the civil Governor of Vyborg (1797-1799) from the Emperor Paul I. Upon retirement, he moved to Hapsal and was signed up for the Estland nobility (1815). His life is a typical example of the service of a not highborn nobleman who used his kinship relations and the membership in the Masonic Lodge for the career growth. Due to this, he achieved a prominent position in the society. The study is carried out on the basis of documents and reference books of their time. It is interesting as an experience of creating a historical portrait of an administrator of the «second plan» within the administrative apparatus of the Russian Empire of the second half of XVIII - early XIX centuries.