The book highlights the complex problems of Slavic ethnogenesis and the origin of the Ukrainian and other East Slavic peoples. Particular attention is paid to the development of ethnocultural and social processes, the Great resettlement of the Slavs, which led to the birth of all Slavic peoples in the early Middle Ages. An important place is occupied by the issues of the formation of the Kyiv-Russian state and criticism of the concept of "Old Russian nationality."