(Russian, etnogenez), the process whereby an ethnic community is formed from various ethnic components.

When ethnogenesis, which is the initial stage in ethnic history, reaches completion, the ethnos that has formed may assimilate other groups or break up into new ethnic groups. Historically, two types of ethnogenesis are distinguished. The first, which is part of the ethnic history of primitive communal and precapitalist societies, concludes with the formation of nationalities, primarily in the early feudal period. In ethnogenetic processes of the second type, members of peoples that have already formed and the processes of acculturation play a decisive role in the formation of modern ethnic communities, such as the contemporary peoples of America.

Ethnogenesis is characterized by the interrelationship of two kinds of ethnogenetic processes. The first is the consolidation of autochthonous ethnic components, both related and unrelated; the second is the inclusion of immigrants in the process of ethnogenesis.

The study of ethnogenesis requires an interdisciplinary approach that uses data from the related disciplines of archaeology, comparative linguistics, and cultural and physical anthropology.