A medievalist by profession, Ryszard Marciniak was associated with two research libraries in Wielkopolska: the Kornik Library of the Polish Academy of Sciences (1965-1980) and the Library of the Poznan Science Society (Biblioteka Poznanskiego Towarzystwa Przyjaciol Nauk,1980-2009) where he was director. He also took part in the teaching of librarians at the Adam Mickiewicz University in Poznan and was a distinguished manuscript expert, author of manuscript catalogues, historian of libraries and historian of the region. The authors of the article present the figure and achievements of Ryszard Marciniak set against the background of the situation of Polish libraries, referring to his own opinions. The article includes a bibliography of Marciniak's selected publications on book and library science.
