Located in the basement of a government building in the heart of London, the Cabinet War Rooms were hurriedly converted on the eve of the Second World War to emergency underground accommodation to protect the Prime Minister and the British Government against air attack. In operational use from 27 August 1939 to the Japanese surrender in 1945, these rooms were to become the vital nerve-centre used by Winston Churchill, his War Cabinet and the Chiefs of Staff of Britain's armed forces.