For the first sixteen years of its existence, the British Broadcasting Corporation (BBC) conducted its activities exclusively in the English language. The Empire Service launched by the Corporation in 1932, though intended to reach the far corners of the globe, was intended primarily for Britons in the British Empire’s dominions and colonies (though the BBC’s executives recognized that English-speaking natives of these lands could and would occasionally tune in). This changed in January of 1938 with an Arabic language broadcast that inaugurated the BBC Arabic service, the primary building-block of what came to be the BBC World Service. Beginning with an analysis of the modalities through which wireless broadcast technology came to be seen as the primary mode of mass communication, this paper examines the place of radio in British imperial strategies and tactics as the unrivalled mass-cultural tool of empire. Though the connections between culture and imperialism have been the object of much study in recent decades, especially as they manifest as representational practices, the processes pertaining to cultural imperialism as an institutionalized set of historical practices remain understudied. Focusing on the British Empire in the early twentieth century, this paper traces the beginnings of the BBC World Service (inaugurated in 1938) to argue that the period between the world wars witnessed the transition in imperial cultural politics from a near-exclusive focus on native elites to a concern with mass culture, arguing further that Egypt was of unparalleled importance for this major shift in the conduct of British imperial and foreign policy. Using the BBC’s own written archives and the transcriptions of the early BBC Arabic broadcasts, together with records from the British Foreign and Colonial offices and the India office, I outline the contours of the debates among officers of the British Empire surrounding Arabic language broadcasts. By doing so, I show that the establishment of BBC Arabic was not only a British response to the Arabic language broadcasts of Mussolini’s Radio Bari—the factor most often cited in the scholarly literature to explain the emergence of BBC Arabic—but that a much broader set of transformations were involved, ranging from the role of propaganda in the conduct of British foreign policy, the broadening of the target of such propaganda from ruling elites to educated publics, and the place of Egypt in particular in transforming mass culture into an arena of imperial politics.