The Jagiellonian Library houses the Birkenmajer family archive bought in 1971-1975. The biggest part of it consists of a 591-volume collection of Aleksander Birkenmajer's manuscripts (catalogue no. rkp BJ Przyb. 605-622/73, Przyb. 151-724/75). The archive also comprises papers belonging to his grandfather, Franciszek Michal Karlinski (1830-1906), his father Ludwik Antoni Birkenmajer (1855-1929) and other family members. Aleksander Birkenmajer's biographical material fills 22 folders and includes, among others, notes from his student days at the Jagiellonian University and various notebooks. Typescripts and drafts of A. Birkenmajer's works, often with additional notes and accompanying correspondence, fill 241 folders (containing: PhD thesis 'Henryk Bate z Mechlinu' (Henry Bate of Mechelen); studies on Nicolaus Copernicus and 'Objasnienia' (Commentary) to the critical edition of Book I of 'O obrotach...' (De revolutionibus...) from 1953; dissertations on Aristotle and Witelon; addendum (devoted to the history of the Polish books) to the translation of Sven Dahl's 'History of the book', studies devoted to the history of libraries and historical bindings, materials to be used for the compilation of entries in the 'Polish Biographical Dictionary', numerous reviews).The legacy also contains research materials in the form of extracts from catalogues of manuscripts from numerous European libraries, detailed descriptions of manuscripts and their photographs as well as press cuttings. There are also notes given to Birkenmajer by the Danish scholar Alex Anton Bjornbo in 1911. Materials included in the archive document Aleksander Birkenmajer's multifaceted professional and research activities, including his participation in the work of a committee dealing with the recovery of various collections after WWII. There are also surviving documents dealing with his numerous research-related journeys, participation in conferences and symposia all over the world, materials associated with his didactic and library work (including the issue of constructing libraries). An important source of information about Aleksander Birkenmajer's work is the 91-volume correspondence (including 3 volumes of family correspondence, 12 volumes of Birkenmajer's letters in the form of drafts or copies, and letters from about two thousand correspondents, both private individuals and institutions).