The book by French historian Jean Savan is devoted to the history of the military service class, which stood guard over the borders of the Russian Empire and at the origins of its statehood. The author traces the centuries-old path of the Cossacks from free communities to service in the Guard regiments of the Russian Imperial Army, describes the history of the emergence of eleven Cossack troops who took part in military campaigns, the conquest of Siberia and the development of the lands of the Far East. Professor Savan, based on ethnographic research, talks about the unique external features characteristic of the Cossacks and Cossacks of the Don Army Region, the Caucasus, the Urals, Transbaikalia and other places of settlement, about the traditions and customs of free people who preserved not only the memory of military glory, but also an original creative heritage.