Troops, warships and neutral countries, 1939–1940

German soldiers in field caps march with machine guns on their shoulders, and men in dark coats and young soldiers with kit bags go off to their units. Heavy warships steam through a rolling swell, a periscope breaks the surface and a ship blows apart. Skaters glide beneath Dutch windmills, cyclists crowd a street, and people stand before the wooden houses on the harbour of Bergen.

After the defeat of Poland in September 1939 the war in the west came to a standstill. Britain and France waited behind their frontiers, the war at sea went on, and the neutral states – Denmark, Norway, the Netherlands and Belgium – hoped to stay out of it. In the spring of 1940 all four were invaded.