The monograph summarizes the results of many years of research on monuments of the Iron Age and the Early Middle Ages found in the Republic of Sakha (Yakutia). Based on an exhaustive analysis of materials on archeology, ethnography and anthropology, the author offers his options for solving the problems of their periodization and chronology, reconstructs the spiritual and material culture of the inhabitants of the Lena region in the Iron Age. In the context of all this, a peculiar concept of ethnogenesis of the indigenous peoples of Yakutia is proposed.