Namestnik (Russian: Наместник) was an office position in the history of Russia. Its literal translation would be "deputy". The term has two periods of usage, with different meanings.

In 12th-16th centuries namestniks (more correctly knyaz namestniks, or "knyaz deputies") were in charge of local administration. In particular, they ruled uyezds. Kniaz’ or knyaz (князь in Russian and Ukrainian; cneaz in Romanian fem. ... Uyezd was a division of guberniya. ...

In 18th-20th centuries a namestnik was a person in charge of namestnichestvo, with plenipotentiary powers. The latter has traditionally been translated as viceroyalty and "namestnik" as viceroy or vicegerent (or, as a common blunder, "viceregent"). For example, Mikhail Vorontsov was namestnik of Bessarabia (1823-44) and Caucasus (1844-1854). Sometimes the term is confused with Governor General (генерал-губернатор), which is not correct. For example, it is known that during Voronsov's office in Bessarabia, 7 governor-generals have been changed, and at the same time he had a different office of Governor General of New Russia. The term plenipotentiary (from the Latin, plenus + potens, full + power) refers to a person who has full powers. ... A viceroy is somebody who governs a country or province as a substitute for the monarch. ... A viceroy is somebody who governs a country or province as a substitute for the monarch. ... The official administrative deputy of a ruler or head of state. ... Prince Mikhail Semyonovich Vorontsov (1782–1856), was a Russian prince and field-marshal, renowned for his success in the Napoleonic wars, and most famous for leading the Russian invasion of the Caucasus from 1844 to 1853. ... Old map of Bessarabia Bessarabia or Bessarabiya (Basarabia in Romanian, Besarabya in Turkish) was the name by which the Imperial Russia designated the eastern part of the principality of Moldavia annexed by Russia in 1812. ... The Caucasus is a region in Eastern Europe between the Black Sea and the Caspian Sea which includes the Caucasus mountains and surrounding lowlands. ... Governor-General (or Governor General) is a term used both historically and currently to designate the appointed representative of a head of state or their government for a particular territory, historically in a colonial context, but no longer necessarily in that form. ... Novorossiya (Russian: , literally New Russia) is a historic area now mostly located in southern Ukraine, and partially in southern Russia. ...