The collective monograph is devoted to the study of ethnocultural processes of the Middle Ages in the Baikal region. Considering this territory expansively - within the framework of the Pre-Baikal region, Transbaikalia and the Circum-Baikal region, the authors define it as the historical border zone of the early Turkic-Mongolian-Samoyed-Tungusic-Paleoasian contacts, and against this background they focus on the problems of ethnogenesis and ethnic history of the Buryats and Yakuts. An attempt was made by researchers of different scientific schools to comprehend the common genetic roots and deep foundations of the culture of ancestral ethnic groups, to study in more detail the late ethno-evolutionary processes and historical destinies of these peoples in their places of modern residence. The reader will notice the novelty of the methodological vision of the problems under consideration and the original interpretation of issues of ethno- and cultural genesis.