Operation Avalanche and the Italian mainland. The Allied invasion of Sicily in July 1943, codenamed Operation Husky, was highly successful, although many of the Axis forces there were allowed to avoid capture and escape to the mainland. More importantly a "coup" deposed Benito Mussolini as head of the Italian government, which then began approaching the Allies to make peace. It was believed a quick invasion of Italy might hasten an Italian surrender and produce quick military victories over the German troops that would now be trapped fighting in a hostile country. However, Italian (and more so German) resistance proved relatively strong, and
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