
Sea Lion was never taken beyond the preliminary assembly of forces. The rapid construction of field fortifications transformed much of the United Kingdom, especially southern England, into a prepared battlefield. 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. Detail from a pillbox embrasure.īritish 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 ( Operation Sea Lion) by German armed forces in 19.


A British soldier guards a beach in Southern England, 7 October 1940.
