This book analyses the attempts of the British Broadcasting Corporation (BBC) to use broadcasting as a tool of empire. From an early stage the corporation sought to unite home listeners with their counterparts in the wider British world, particularly in the British settler diaspora in Canada, Australia, New Zealand, and South Africa. The BBC saw this as part of its public-service mandate, and also as a means to strengthen its position at home: by broadcasting to and about the empire, it built up its own broadcasting empire. The BBC encouraged overseas the spread of the British approach to broadcasting, in preference to the American commercial model. During the 1930s it tried to work with the public broadcasting authorities that were established in the ‘dominions’: initially, these efforts met with limited success, but more progress was made in the later 1930s. High culture, royal ceremonies, sport, and even comedy were used to project Britishness, particularly on the BBC Empire Service, the predecessor of today's World Service. Commonwealth broadcasting collaboration intensified during the Second World War, and reached its climax during the late 1940s and 1950s. Belatedly, at this stage the BBC also began to consider the role of broadcasting in Africa and Asia, as a means to encourage ‘development’ and to combat resistance to continued colonial rule. However, during the 1960s, as decolonization entered its final, accelerated phase, the BBC staged its own imperial retreat.