How does a national awakening happen? After Finland passed from Swedish to Russian rule in 1809, part of the remaining Swedish-speaking elite founded the Fennoman movement and started to vigorously promote a separate Finnish national identity. We assemble a network of 17,481 nineteenth-century elites from biographical records, university registers, and private correspondence, and date individual's entry into the nationalistic Finnish Literature Society to track the diffusion of national awakening. We document that the adoption began among those closest to the movement's founders, and then diffused along network ties. An individual's annual probability of joining more than tripled, from 0.2 to 0.7 percent, once an adjacent connection had joined. We provide evidence that the elites then spread the national idea to non-elites.  At the local level, exploiting an exogenous shift in Fennoman influence due to tsar Alexander II's accession, a difference-in-differences design shows that municipalities with more initial Fennoman elites experienced a sharper and persistent shift toward more nationalistic child naming practices among the broader population. The more exposed municipalities further exhibited lasting effects of higher nationalist party vote shares, more nationalist newspaper subscriptions, and more pronounced mass finnicization of names among the non-elites in the early 1900s. We explore letters to the press and Finnish-language schooling as two potential channels through which the elite nation-building movement reached the non-elites. Our results highlight how a relatively small group of cultural elites can substantially influence the creation of national identity.