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 Poland had been completely overrun. There was little fighting over the months that followed. In a period known as the Phoney War, soldiers on both sides trained for war and the French and British constructed and manned defences on the eastern borders of France. On 9 April 1940, Germany invaded Denmark and Norway. This operation preempted Britain's own plans to invade Norway. Denmark surrendered immediately, and, after a short-lived attempt by the British to make a stand in the northern part of the country, Norway also fell. The invasion of Norway was a combined forces operation in which the German