The ethnogenesis of the Alans represents a complex process of tribal confederation and cultural synthesis that was typical of steppe societies. Archaeological evidence suggests that the peoples who would become known as the Alans were descendants of earlier Scythian and Sarmatian populations who had inhabited the region between the Don and Volga rivers since at least the fourth century BCE. These earlier Iranian nomads had already established patterns of pastoral nomadism, warrior culture, and political organization that would become characteristic features of Alan society. The transition from these earlier groups to the historically documented Alans appears to have occurred gradually, as tribal confederations formed and reformed in response to population pressures, climate changes, and interactions with sedentary civilizations.