The collection includes transcripts of the meeting of the Military Council under the NPO of the USSR on June 1-4, 1937 and the meeting of the asset of the central office of the NPO of the USSR on June 9-10, 1937; orders of the NPO of the USSR on a "conspiracy" in the Red Army; investigative testimonies and letters of M.N. Tukhachevsky, V.K. Putny, N.E. Yakir about the state and combat readiness of the Red Army; materials on the results of repressions and personnel appointments in the Red Army for 1937-1940. Most of the documents and materials of the collection are published for the first time and make it possible to objectively assess the events that served as the beginning of mass repressions against the command personnel of the Red Army. The book is designed for specialists - researchers of Russian history, as well as for a wide range of readers.