Chapter 1 of the history course A New Imperial History of Northern Eurasia is titled “Political Ecology: Formation of the Region of North Eurasia.” It proceeds from surveying the climate and landscape zones of the region that affected the social organization of various groups of its inhabitants. The region itself was an entity only in one sense: as defined negatively, as the spaces not claimed (or explored) by the great ancient civilizations that formed the “southern belt,” from China, through the Sassanian neo-Persian Empire, to the East Roman (Byzantine) Empire. The diverse and half-isolated communities of nomads, forest inhabitants, and hunters of the Far North probably did not even have a need to conceptualize their lands in terms of a “region.” However, as they began working out their particular ecological niches into primitive political unions sometime in the middle of the first millennium CE, they acquired an important common quality that allows us retrospectively to see them as inhabitants of the same sphere. That sphere can be defined in sociopolitical rather than geographic terms: as the space of societal and political self-organization of a people that could not rely on some preexisting traditions of statehood (whether Chinese, Persian, or Byzantine). The alternative scenarios of political and cultural self-organization adopted in various corners of the would-be region of North Eurasia became the driving force of its historic dynamic that would entangle them and, eventually, bring them together as a distinctive historical and cultural region.