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 American Fifth Army and General Bernard Montgomery's British Eighth Army) and followed the successful Allied 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).
Salerno suffered a great deal of damage. Henry Wellesley, 6th Duke of Wellington, who was killed in action during the fighting, is buried in Salerno War Cemetery. From 12 February to 17 July 1944, it hosted the Government of Marshal Pietro Badoglio.