The Reich Labour Service at work and at school, 1937

Six great penstocks run down a wooded mountainside beneath a pylon. Young men walk in file through a pine wood by a lake, then stand knee-deep in a new canal, stripped to the waist, shovelling gravel, tipping barrows and paving the embankment; a leader in a peaked cap blows his whistle and the resting gang goes back to work. On an alpine meadow dozens of them sit in their bathing trunks while an instructor points to a world map on an easel.

From June 1935 every young German man owed six months to the Reich Labour Service before joining the army. Its leader Konstantin Hierl, a former general staff officer, ran it like a barracks; the spade was its weapon, and the political lessons taught that Germany needed more living space.