British anti-invasion preparations of the Second World War
After the defeat of British forces in Dunkirk in 1940, the army needed to recover and respond to the threat of invasion known as Operation Sea Lion.
As a result 1.5 million men were recruited into the Home Guard.
Coastal fortifications were rapidly constructed along the country's coasts, especially in southern England, transforming its beaches into ready-made battle grounds in preparation for any potential German invasion.
In all, a total of 153 Emergency Coastal Batteries were constructed in 1940 in addition to the existing coastal artillery installations, to protect ports and likely landing places.
Beaches were marked with metal posts and barbed wire that would also serve to mark out anti-personnel and anti-tank minefields.