- Theatre: Mediterranean
- Dates: 3 to 16 September 1943
- Location: Reggio, Salerno and Taranto, southern Italy
- Outcome: Allied breakout from initial beachheads to hold extensive areas of southern Italy.
- Allies: General Bernard Montgomery's 8th Army (consisting of 5th Corps and 13th Corps); General Mark Clark's US 5th Army (consisting of 6th Corps and the British 10th Corps)
- Axis: General Heinrich von Vietinghoff's German 10th Army
On 3 September 1943, 13th Corps of Montgomery's 8th Army crossed the Straits of Messina from Sicily to mainland Italy. The crossing, preceded by a massive artillery bombardment of the Italian shore, was uneventful; the 8th Army established itself in the town of Reggio, facing Messina, without serious opposition.
Further progress northward was more difficult. After the Allied conquest of Sicily, German forces had largely abandoned the south of Italy, but not before sabotage groups were deployed to slow the Allied advance: roads were mined and bridges blown up.
Advancing up both coasts of the south western 'toe' of boot-shaped Italy, 13th Corps' progress was slow. On 10 September the Corps paused to regroup at Nicastro and Catanzaro, about 160km (100 miles) north of Reggio; there was no further progress until 14 September. By then, the 8th Army's 5th Corps had established itself at Taranto in south east Italy following landings of airborne troops on 9 September.
Both the 8th Army landings were organised in support of the primary Allied landing in mainland Italy, Operation Avalanche. This took place at Salerno on 9 September, carried out by Clark's US 5th Army. Several factors conspired against this landing:
- The delays to the 8th Army's progress meant that Montgomery's forces were initially unable to support the American landing as planned.
- Salerno, a bay offering 32km (20 miles) of beach within aerial striking range of Sicily, was the best possible landing site in the area; as such, the Germans anticipated that it would be used.
- Secret negotiations with Mussolini's successor, Marshal Pietro Badoglio, had resulted in the formal surrender of Italy to the Allies; agreed on 3 September, this was announced on 8 September. German forces immediately moved to occupy Rome and replace Italian garrisons throughout the country.
- German military strategy in Italy had changed just before the landings. The previous policy, laid down by Field Marshal Erwin Rommel, who was in charge of German troops in the north of Italy, had advocated a retreat to positions north of Rome. But Rommel's southern counterpart, Field Marshal Albert Kesselring, succeeded in committing the German army to holding its positions in the south.
As a result of all these factors, the landing at Salerno was fiercely contested; at one point Clark even began preparing to evacuate. The original objective of securing Naples, 80km (50 miles) away, was rapidly abandoned in favour of holding the Salerno beachhead.
Supported by naval and aerial bombardment, the 5th Army held off concerted German assaults on 13 and 14 September. With the arrival of the 8th Army, the tide turned; on 17 September Vietinghoff called off the attempt to repel the Allies. German forces in Italy were now reorganised under the sole command of Kesselring, who prepared a series of defensive lines, from the Viktor Line north of Naples to the Gothic Line above Florence.
The Salerno landing was hard fought; so was the campaign that followed. Naples fell on 30 September, three weeks after the landing. The tenacity and efficiency of German resistance destroyed any notion of Italy as the 'soft underbelly' of Europe, as Churchill had called it. It also ruled out any prospect of using Italy as the base for a 'second front' attack on Nazi-held Austria during the invasion of north west Europe.
What the landing did make possible was a campaign that diverted substantial German forces away from Normandy ahead of the D-Day landings in June 1944. It also liberated Italy from Nazism.