The Allied Invasion of Sicily represented the beginning of the Italian campaign and ended with the occupation of the island by the Allies.
An invasion of Italy had two advantages for the Allies. First, could lead to the exit from the war of the biggest European state allied with Germany, and secondly, it would engaged the German military resources on a secondary front.
During the months prior to the invasion of Sicily, the British and American air forces had launched a campaign of strategic bombing on the airfields, ports and industrial areas in southern Italy, Sicily, and Sardinia. Not only in this way the enemy did not know exactly where the invasion would take place, but the bombings weakened the Luftwaffe and Aeronautica Militare Italiana, which was vital to protect the invasion forces.
Most of the Axis troops in Sicily were Italian, about half of the Italian infantry being used as fixed defense around the main port areas. At the start of the Allied invasion, the Wehrmacht had in Sicily the 15th Panzergrenadier Division and the Panzer Division Hermann Goering.
Bundesarchiv, Bild 183-J14953 / [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0/de/deed.en], via Wikimedia Commons
The Allied invasion of Sicily, code-named Operation Husky, began on the night of 9/10 July 1943 when paratroopers from the British 1st Airborne Division and U.S. 82nd Airborne Division were dropped to occupy airfields and strategic bridges near the naval landing zones. The strong wind caused the scattering of the airborne troops on a vast area but, nevertheless, the small groups of paratroopers began the harassment of the enemy.
The amphibious landings were divided in two main areas. In the first wave, the British Eighth Army, under General Bernard Montgomery, landed four infantry divisions in the southeast of the island, including a Canadian division, and an independent infantry brigade. The U.S. Seventh Army, led by Lieutenant General George S. Patton, landed three infantry divisions in the south of the island, in the first wave, and an armored division that would gradually enter into battle.
Resistance was generally weak in the landing areas, the port of Syracuse being occupied by the British until the end of the first day. However, after the initial shock, the Axis forces counterattacked. The Italian Infantry Division Napoli attacked the British with Renault R-35 tanks, while the Italian Infantry Division Livorno and the Panzer Division Hermann Goering attacked the American sector but the artillery fire of the U.S. Navy helped to disperse the attacks.
Albert Kesselring, commander of the German forces in Italy, decided shortly after the start of the invasion to withdraw the Axis forces on a shorter defense line in the northeastern Sicily, with Mount Etna behind them. He also sent reinforcements consisting of Fallschirmjäger and Panzergrenadier units.
Following the Germans retreat from Western Sicily, the U.S. Army advanced rapidly, taking the port of Palermo on 22 July. The British instead met a stiff German opposition, managing to conquer the port of Catania only on 3 August.
However, what mattered was that the Germans had already decided to evacuate the island and therefore fought in a controlled retreat. On 16 August, the Americans entered Messina - the last port still unoccupied - bringing thus the whole of Sicily into Allied hands.
The Italian fascist leader Benito Mussolini had been overthrown even before the battle for Sicily to be concluded. The Allied victory in Sicily weakened even more the alliance between Italy and Germany.