Mussolini, who was rescued by German paratroopers, established a collaborationist puppet state, the Italian Social Republic (RSI), to administer the German-occupied territory.

Both sides committed war crimes during the conflict, and the independent states of San Marino and Vatican City surrounded by Italian territory also suffered damage.

The strategic disagreement was fierce, with the U.S. service chiefs arguing for an invasion of France as early as possible, while their British counterparts advocated a policy centred on operations in the Mediterranean.

[33] The American staff believed that a full-scale invasion of France at the earliest possible time was required to end the war in Europe, and that no operations should be undertaken that might delay that effort.

Eventually the U.S. and British political leadership reached a compromise in which both would commit most of their forces to an invasion of France in early 1944, but also launch a relatively small-scale Italian campaign.

[36][37] The elimination of Italy would enable Allied naval forces, principally the Royal Navy, to dominate the Mediterranean Sea, securing the lines of communications with Egypt and thus Asia.

When the Eighth Army were held up by stubborn defences in the rugged hills south of Mount Etna, Patton amplified the American role with a wide advance northwest toward Palermo and then directly north to cut the northern coastal road.

The defending German and Italian forces were unable to prevent the Allied capture of the island, but they succeeded in evacuating most of their troops to the mainland, with the last leaving on 17 August 1943.

Forces of the British Eighth Army, still under Montgomery, landed in the 'toe' of Italy on 3 September 1943 in Operation Baytown, the day the Italian government agreed to an armistice with the Allies.

There had been a hope that, with the surrender of the Italian government, the Germans would withdraw to the north, since at the time Adolf Hitler had been persuaded that Southern Italy was strategically unimportant.

In the most mountainous areas of Abruzzo, more than half the width of the peninsula comprises crests and peaks over 900 metres (3,000 feet) that are relatively easy to defend; and the spurs and re-entrants to the spine confronted the Allies with a succession of ridges and rivers across their line of advance.

This would make the most of the natural defensive geography of Central Italy, whilst denying the Allies the easy capture of a succession of airfields, each one being ever closer to Germany.

Hitler was also convinced that yielding southern Italy would provide the Allies with a springboard for an invasion of the Balkans, with its vital resources of oil, bauxite, and copper.

Although the Gustav Line was penetrated on the Eighth Army's Adriatic front, and Ortona was liberated with heavy casualties to Canadian troops, the blizzards, drifting snow and zero visibility at the end of December caused the advance to grind to a halt.

It took four major offensives between January and May 1944 before the line was eventually broken by a combined assault of the Fifth and Eighth Armies (including British, American, French, Polish, and Canadian corps) concentrated along a 30-kilometre (20-mile) front between Monte Cassino and the western seaboard.

In a concurrent action, Clark was ordered to break out of the stagnant position at Anzio and cash in on the opportunity to cut off and destroy a large part of the German 10th Army retreating from the Gustav Line between them and the Canadians.

Churchill's proposal had been strongly opposed by the U.S. Chiefs of Staff, despite its importance to British postwar interests in the region, as they did not believe that it aligned with overall Allied war priorities.

The poor winter weather, which made armoured manoeuvre and the exploitation of overwhelming air superiority impossible, coupled with the massive losses suffered to its ranks during the autumn fighting,[48][49] the need to transfer some British troops to Greece (as well as the need to withdraw the British 5th Infantry Division and I Canadian Corps to northwestern Europe) made it impractical for the Allies to continue their offensive in early 1945.

[7] By 18 April, Eighth Army forces in the east had broken through the Argenta Gap and sent armour racing forward in an encircling move to meet the U.S. IV Corps advancing from the Apennines in Central Italy and to trap the remaining defenders of Bologna.

[56] By 25 April, the Italian Partisans' Committee of Liberation declared a general uprising,[57] and on the same day, having crossed the Po on the right flank, forces of the Eighth Army advanced north-northeast towards Venice and Trieste.

[52] General Heinrich von Vietinghoff, who had taken command of Army Group C after Albert Kesselring had been transferred to become Commander-in-Chief of the Western Front (OB West) in March 1945, signed the instrument of surrender on behalf of German forces in Italy on 29 April, formally bringing hostilities to an end on 2 May 1945.

[61] Approximately 14,000 Italian non-Jewish civilians, often women, children and elderly, have been documented to have died in over 5,300 individual instances of war crimes committed by Nazi Germany.