[T]he single largest social experiment in Great Britain during World War II [was] the official evacuation of between 800,000 and a million children, mostly unaccompanied, from London and other cities of Great Britain in order to transfer them away from aerial bombing of industrial centers. The evacuations occurred in three waves - the first (and largest) occurring before bombing began, between September 1-3, 1939; the second after the beginning of the “blitz” in 1940; and the last when the V-1 and V-2 rockets attacked London and the southeast of England in 1944. . . . The greatest effect of the wartime experiment . . . was on overall social policy. Evacuation of chiefly poor children from the inner cities to the more affluent countryside exposed the persistence of poverty to the nation. Shining a light on the “dark places” in turn helped to inspire the post-war construction of the welfare state, including national health insurance.
The evacuation provides the frame for the Narnia Chronicles by C.S. Lewis whose prestige as a Christian apologist was also greatly enhanced by his BBC lectures during that period making him one of the world's earliest prominent televangelists.