The reviewer analyzes the materials included into the book “The great librarian: Eduard Rubenovich Sukiasyan” [in Russian] (Великий библиотекарь: Эдуард Рубенович Сукиасян = The Great Librarian: Eduard Rubenovich Sukiasyan // Russian State Library; [Comp. by T. F. Bakhturina, N. N. Golodnova, E. V. Kononova and A. B. Khaitseva]. Moscow : Pashkov dom, 2023. 588 p. : Ill. Parallel title page in English. ISBN 978-5-7510-0848-2), e. g. biographical data, several articles and fragments of unpublished works, reminiscences of Sukiasyan's colleagues on their joint work, meetings at conferences, and historical photos. The reviewer emphasizes the personal, expressive and emotional style of the materials that evidence on Sukiasyan's outstanding personality. E. R. Sukiasyan was the Editor-In-Chief of the Russian Library Bibliographic Classification (LBC). The authors of the book articles portray his unique character, widely recognized expertise of the professional and scholar, whose significant achievements are used by every Russian library.