This chapter describes the growing imperative in nineteenth-century India to carve out geographically distinct social-linguistic zones where only one Indian language could officiate. By doing a transnational history of the shifting understanding of the sociopolitical role of popular mother tongues, I show how the use of “vernacular” as a common epithet for some Indian languages came to imbue these tongues with meanings that drew from European debates on language and freedom. Once Britain colonized India, major Indian languages came to be called vernacular. The “vernacular” in its Indian career was an underdeveloped mother tongue whose recuperation and use in education, revenue, and judicial administration was thought to be crucial to liberal governance. Through a history of successive colonial policy decisions to use vernaculars in education and governance in India as well as the concomitant local debates about boundaries between the geographical domains of Indian languages such as the Odia/Bengali debate of the 1860s and 1870s, I illustrate the peculiar politics of colonial vernacularization. The very processes of insistent localization and denigration of Indian languages created the conditions of possibility of the simultaneous empowerment of these languages as languages of state. To be vernacular was to be both popular and elite in regional India.