This dissertation argues that before the rise of television and the loss of its monopoly in 1954, the British Broadcasting Corporation was the most important arena in British society where regional cultures interacted with and interrogated a normative English culture, helping to create the hybrid dual identities of contemporary Britain. The BBC was a nationalizing institution, uniting people across the United Kingdom into a community of British listeners, regardless of class, gender, or ethnicity. Its programs stressed the importance of national unity, especially from the late 1930s, when fascism threatened to undermine British identity. Yet, in its policies and programs, the BBC created spaces for the expression of other national identities in Britain: Scottishness, Welshness, and Ulsterness. Drawing primarily on archival and published primary sources, and using the methodology of the "four nations" approach to British history, this dissertation explores the changing contours of the BBC's representation of Britishness. The BBC used two British institutions, in particular, to construct a unitary, consensual British national identity, the Empire and the Monarchy. The BBC vigorously projected the Empire, often representing it as the common heritage and destiny of all the peoples of Britain. The BBC promoted Empire into the 1950s, after the process of decolonization was underway, suggesting that a kind of imperial culture lasted in Britain well after the end of the Second World War. The BBC also constructed the Monarchy as an institution to which Britons could safely profess their loyalty as an expression of their British nationality, without compromising their Scottish, Welsh, or Irish identities. Similarly, the BBC did not act as an agent of Anglicization or English cultural hegemony, but rather it fostered the development of national identity in Scotland, Wales, and Northern Ireland. The BBC established radio networks, responsible for reflecting the geography, history, and culture of their locality, in each of these regions. Although part of the BBC, the regional radio networks fought for, and were given, considerable autonomy, enabling them to engage in a limited, but significant, nation building program. Source: Dissertation Abstracts International, Volume: 67-01, Section: A, page: 0300. Adviser: Thomas William Heyck. Thesis (Ph.D.)--Northwestern University, 2005.