Allied invasion of Italy Allied invasion of Italy The Allied invasion of Italy was the Allied amphibious landing on mainland Italy that took place on 3 September 1943 during the early stages of the Italian Campaign of World War II. The operation was undertaken by General Sir Harold Alexander's 15th Army Group (comprising General Mark W. Clark's Fifth Army and General Bernard Montgomery's British Eighth Army) and followed the successful invasion of Sicily. The main invasion force landed around Salerno on 9 September on the western coast in Operation Avalanche, while two supporting operations took place in Calabria (Operation Baytown) and Taranto (Operation Slapstick).
British anti-invasion preparations of the Second World War 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. The German invasion plan, Operation Sea Lion, was never taken beyond the