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
Allied invasion of Italy Operation Avalanche–the main invasion at Salerno by the American Fifth Army under Lieutenant General Mark Clark–began on 9 September 1943, and in order to secure surprise, it was decided to assault without preliminary naval or aerial bombardment. However, as Admiral Henry Hewitt, the amphibious force commander, had predicted, tactical surprise was not achieved. As the first wave of Major General Fred Walker's U.S. 36th Infantry Division approached the Paestum shore at 03:30 a loudspeaker from the landing area proclaimed in English: ""Come on in and give up. We have you covered."" The Allied troops attacked nonetheless. Major General Rudolf Sieckenius,