The article deals, based on the archival documents and published materials, with the contribution of the well-known folklorist and literary critic Yuri Matveyevich Sokolov (1889–1941) to the development and formation of the Library of the State Historical Museum in the post-revolutionary period, and his activities as head of the museum library in 1922–1929, as well, as the circumstances of his forced departure from the Historical Museum due to the conflict with the Museum's management. A number of published documents are being introduced into scientific circulation for the first time.

Based on a wide range of archival documents, the biographies of Siberian “fiery revolutionaries” – Alexander Vasilievich Tsytovich (1873–1942) and his wife – Anna Pavlovna, nee Tarelkina (1879 – after 1957), active participants in the Irkutsk Social Democratic underground of 1904–1912, then – of political emigrants. Information is presented on the activities of A.V.Tsytovich after returning to Soviet Russia in 1919, on his work as director of the Library of the State Historical Museum (1929–1933).