Allied invasion of Italy of historian Carlo D'Este, Clark "mistakenly believed he had saved the Allied invasion by his leadership, when in fact it was precisely his inexperience that precipitated most of the problems the invasion force faced." 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
Operation Avalanche the Allied armies a grinding and attritional slog against skillful, determined and well prepared defenses in terrain and weather conditions which favoured defense and hampered the Allied advantages in mechanised equipment and air superiority. It took until mid-January 1944 to fight through the Volturno, Barbara and Bernhardt lines to reach the Gustav Line, the backbone of the Winter Line defenses, setting the scene for the four Battles of Monte Cassino which took place between January and May 1944. Operation Avalanche Operation Avalanche was the codename for the Allied landings near the port of Salerno, executed on 9 September 1943, part