The Allied invasion of Italy was the Allied landing on mainland Italy on 3 September 1943 during the Second World War, by British General Harold Alexander's 15th Army Group (comprising Lieutenant General Mark Clark's United States Fifth Army and General Bernard Montgomery's British Eighth Army). The operation followed the successful invasion of Sicily during the Italian Campaign. The main invasion force landed around Salerno on the western coast in Operation Avalanche, while two supporting operations took place in Calabria (Operation Baytown) and Taranto (Operation Slapstick).