British anti-invasion preparations of the Second World War
British anti-invasion preparations of the Second World War entailed a large-scale division of military and civilian mobilisation in response to the threat of invasion by German armed forces in 1940 and 1941. The British Army needed to recover from the defeat of the British Expeditionary Force in France, and 1.5 million men were enrolled as part-time soldiers in the Home Guard. The rapid construction of field fortifications transformed much of the United Kingdom, especially southern England, into a prepared battlefield. Sea Lion was never taken beyond the preliminary assembly of forces. Today, little remains of Britain's anti-invasion preparations, although reinforced concrete structures such as pillboxes and anti-tank cubes can still be commonly found, particularly in the coastal counties.
A British soldier guards a beach in Southern England, 7 October 1940.
Detail from a pillbox embrasure.
Captured British and French soldiers help one another on the staircase up to the cliff at Veules-les-Roses, June 1940
Standard Mk II Beaverette II light reconnaissance cars manned by members of the Home Guard in the Highlands of Scotland, 14 February 1941
Operation Sea Lion, also written as Operation Sealion, was Nazi Germany's code name for their planned invasion of the United Kingdom. It was to take place during the Battle of Britain, nine months after the start of the Second World War. Following the Battle of France and that country's capitulation, Adolf Hitler, the German Führer and Supreme Commander of the Armed Forces, hoped the British government would accept his offer to end the state of war between the two. He considered invasion to be a last resort, to be used only if all other options had failed.
British soldiers in France in 1939
Winston Churchill visiting bomb-damaged areas of the East End of London, 8 September 1940
The Channel (Der Kanal), D.66 Kriegsmarine nautical chart, 1943
Invasion barges assembled at the German port of Wilhelmshaven.