As deputy prime minister of Britain's coalition government during World War II, Clement Attlee became one of the most powerful figures in British politics and subsequently played a crucial role in the reshaping of the post-war political-party landscape. The architect of the Labour Party's entry into the wartime coalition, Attlee came to straddle the workings of government to a unique degree. Unmatched in his range of influence, he dominated party politics; directed a doctrinal struggle within the coalition; and even sought to create the conditions for a cross-party alliance to be maintained...