Researching Historical Library Collections to Discover the Past and Plan the Future.

This paper focuses on the how and what of library history research, and on the study of rare and historical collections, with the University of Warsaw Library as an example. This library was established in 1817 as part of the Royal University of Warsaw. It also served as an independent public library and was regarded as a national library. Since its foundation, it has received and purchased many valuable artistic and historical collections, including the famous Print Room of King Stanisław August Poniatowski and an exceptional collection of nineteenth-century publications, including Rossica (publications in Russian). The author points out the methods needed for this research and for the reconstruction of lost collections, which should combine provenance studies, bibliographical knowledge and archival evidence with a sense of critical synthesis. Digital humanities and semantic encoding can become new tools. [ABSTRACT FROM AUTHOR]