The Great Patriotic War did not begin on June 22, 1941. The book, based on a wealth of factual material, tells about the participation of the Cossacks of all the Cossack troops of Russia - from the Don, Kuban, Terek to the Urals, Orenburg region, Siberia and the Far East - in the dramatic events of Russian history last century. The stages of the emergence and development of the country's Cossack troops, the general situation of the Cossacks at the beginning of the 20th century, the unique system of Cossack self-government and control of Cossack troops, the participation of Cossacks in hostilities during the Russian-Japanese War of 1904-1905, the events of the revolution of 1905- 1907, the bloody battles of the First World War, in the political storms of the February and October revolutions of 1917, the Civil War. The author's use of unknown archival documents, colorful memories of participants in the events described, vivid newspaper and magazine sketches of those turbulent years, and the works of leading Russian, including White émigré, and foreign historians made it possible to objectively and comprehensively highlight the participation of the country's Cossacks in the largest military and internal political crises of the 20th century. , take a fresh look at the little-studied and little-known pages of Russian and Cossack history itself. The book will arouse undoubted interest among anyone interested in the history of the Cossacks and Russia.