Private books collection of Osyp Nazaruk in the V. Stefanyk NSL of Ukraine in Lviv fund

The processed life time publications of O. Nazaruk in the Vasyl Stefanyk National Scientific Library of Ukraine in Lviv fund have been presented. Information is provided about the writer's creative path in parallel with the social and political events of the era. Traditionally for the social stratum of the intelligentsia at the turn of the century, O. Nazaruk supported and promoted the ideas of socialism. At the same time, due to the development of Ukrainian identity in the regions of Galicia, which followed the Revolutionsof 1848 also known as "Spring of Nations", hepl unged into the state-building trends. O. Nazaruk became a member of the Ukrainian Radical Party, where he was for 18 years, and made a certain career, by becoming a member of the main council of the party. During the second Russian (Soviet) occupation, O. Nazaruk has been classified as Ukrainian nationalists, his works were removed from general access and transferred to closed archives. Scientific and bibliographic research and analysis of copies were carried out. It ha shown the way the writer's books went through several collections and collections of book foundations until their discoveries in the funds of exchange reserve fund department of the Vasyl Stefanyk National Scientific Library of Ukraine in Lviv. It has analyzes the typology of publications from the books collection of O. Nazaruk. Investigated author's provenance and ownership inscriptions available publications. Particular attention was paid to his scientific research and culture-historical exploration. Among them special place is occupied by the Roxolana person (Hurrem-Sultan), in whom O. Nazaruk saw an example to follow in difficult times, the pattern of wisdom and patience. Found edition of Nazaruk's lifetime publications, with work records on marginal fields in different languages left by the owner of the books. During the research and disclosure of personality O. Nazaruk, interesting details were revealed from the cultural life of Western Ukraine in the late ХІХ — early ХХ centuries and literary Lviv, in particular.