On the afternoon of June 4, 1940, as 338,000 soldiers were being evacuated from Dunkirk in the desperate effort to save the British Army from annihilation by the German blitzkrieg then steam-rolling across France, Prime Minister Winston Churchill made a stirring, but seemingly unlikely, promise to the House of Commons. “Britain will fight on,” he thundered, “If necessary for years ... if necessary alone ...We shall go back.”
In December 1941, Adolf Hitler boasted to the world that his Third Reich controlled the entire west coast of Europe from the Arctic Ocean to the Bay of Biscay. “It is my unshakable decision”, the Führer added, “to make this front impregnable against every enemy”. To keep his vow, Hitler conceived of an awesome defence line – a broad band of concrete, steel, guns and troops that would follow the shoreline for 2,400 miles. He called it the Atlantic Wall.