Knowledge of archives is a branch of archival science that concerns studying history of archives, their contemporary organisation, as well as history of fonds and collections, including their content. In connection with this, three main research directions might be distinguished as part of the reflection in knowledge of archives. The first one is history of archives as institutions, their tasks, functions, working methods, staff, premises, equipment, and many other aspects. The second one is reflection on organisation of contemporary archives. The third direction is studying archival collections, more specifically – history of archival fonds, their content, and placement. A special place amongst publications in knowledge of archives hold so called reviews in knowledge of archives (Polish przeglądy archiwoznawcze ). They are scientific texts that present, classify, and describe archival materials – historical sources concerning particular topics, created in selected time on some territory, that are stored in particular archives or other institutions serving archival functions. The beginning of the 21 st century is certainly a crisis for knowledge of archives; it can be connected to the decline in arrangement and description, and the regression in the field of the scientific function of archives. Implementation of IT solutions in archives and growing searching possibilities of data bases make us pose the question of justification of archival knowledge endeavours. Meanwhile, though, it is hard to imagine all other branches of archival science without the knowledge of archives. Results of studies conducted as part of the knowledge of archives should satisfy information needs of users and be helpful in providing access to archival materials.