Kazimierz Piwarski (19 February 1903 – 21 July 1968) was a Polish historian, professor of Jagiellonian University in Kraków since 1946 and Poznań University in years 1953-1955, member of Polish Academy of Skills (Polska Akademia Umiejętności, PAU) since 1945, and member of Polish Academy of Sciences (Polska Akademia Nauk, PAN) since 1958. He researched in the history of the Polish provinces of Pomerania, Silesia, East Prussia and also the universal history of the 18th and 20th centuries. He was one of the most noteworthy Polish historians writing about history of Polish-Saxon relations in 18th