This book opens a three-volume edition on the history of the Cossacks of the eastern regions of Russia: the Urals. Siberia and the Far East. The first volume of the series is devoted to the formation of the East Russian Cossacks, its military organization, the relationship between the Cossacks and the state; the participation of Cossacks in the initial development of new lands in the East of Russia; the role of the Cossacks in the military-political and economic development and development of the Eastern Russian regions.