["Nations and Nationalism, EarlyView. ", "\nABSTRACT\nThe modernist argument that the nation of Japan emerged in the Meiji era (1868–1912) has achieved orthodoxy in the field of Japanese history. This article presents a challenge to this orthodoxy. My approach is two‐pronged. First, adopting a descriptive definition of the nation as a politically unified ethnicity, I analyse the social and symbolic processes that contributed to the political unification of ethnically related communities under the rule of the Yamato kingdom in Japan's Kofun period (200–600). Second, redressing a lacuna in the heterodox study of nation formation, I advance a theory of the wider context for the emergence of the Yamato kingdom. Through analysis of the linguistic, archaeological and textual evidence in light of the genomic data, I show that the Yamato kingdom arose in response to movements of people and culture across Northeast Asia in the wake of Inner Asian expansion in Late Antique Eurasia.\n"]