The comprehensive studies on the history of military research libraries are scarce. The authors discuss the history of the library of Imperial Engineering Academy and School; analyze the development of library collection of this institution. The authors chronologize t he h istory o f t he A cademy a nd i ts l ibrary. The relevant regulatory and legal documents that defined the library operation and development, as well as the Academy’s and School’s annual reports, made the basis of the study. The key collection development sources are specified, namely purchase, funded subscriptions to periodicals, free copies of publications by the General Headquarters Military Typography, gifts, and exchange with other institutions. For the first time, the list of employees for the years 1869–1915 is compiled with the specification of their contribution to the library and teaching activities. The authors argue that the Academy’s book collection is the largest research sector library preserving the best military engineering and academic literature of 15th – early 20th centuries