The 'Campaign for Italy' in World War II, also called the 'Liberation of Italy' following the German 'Achse' (ii) occupation in September 1943, took the form of operations between the Allied and Axis forces in and around Italy (9 July 1943/2 May 1945).

The joint Allied Forces Headquarters was operationally responsible for all Allied land forces in the Mediterranean theatre, and both planned and led the invasion of Sicily on 9 July 1943, followed in September by the invasion of the Italian mainland and the campaign in Italy until the surrender of the German armed forces in Italy on 2 May 1945.

It is estimated that between September 1943 and April 1945, between 60,000 and 70,000 Allied and between 38,805 and 150,660 German soldiers died in Italy. The overall total of Allied casualties was about 330,000 and the German figure (excluding those involved in the final surrender) was more than 330,000. Before its collapse in September 1943, Fascist Italy suffered about 200,000 casualties, including more than 40,000 killed or missing, mostly men taken prisoner in the 'Husky' (i) invasion of Sicily and subsequent campaign on that island. More than 150,000 Italian civilians died, as did 35,828 anti-Fascist partisans and other resistance elements, and some 35,000 troops of the Italian Social Republic. On the Western Front of World War II, Italy was the most costly campaign in terms of casualties suffered by infantry forces of both sides, during bitter small-scale fighting around strongpoints at the 'Winter Line', the Anzio beach-head and lodgement, and the 'Gotisch-Linie'.

The 'Husky' (i) invasion of Sicily in July 1943 paved the way to the collapse of the Fascist Italian régime and the fall of Benito Mussolini, who was deposed and arrested by order of King Vittorio Emanuele III on 25 July. The new government signed an armistice with the Allies on 8 September 1943. However, in 'Achse' (ii) German forces quickly seized control of northern and central Italy, and Mussolini, who was rescued by German special forces in 'Eiche' (ii), established a collaborationist puppet state known from December 1943 as the Repubblica Sociale Italiana (Italian Social Republic), to administer the German-occupied territory. The Germans, sometimes with Italian Fascists forces, also committed several atrocities against civilians and non-fascist troops. The Italian Co-Belligerent Army was created to fight against the RSI and its German allies, alongside the large Italian resistance movement, while other Italian troops continued to fight alongside the Germans in the National Republican Army; this period is known as the Italian Civil War. In April 1945, Mussolini was captured by the Italian resistance and summarily executed by firing squad. The campaign ended when Generaloberst Heinrich-Gottfried von Vietinghoff-Scheel’s Heeresgruppe 'C' surrendered unconditionally to the Allies on 2 May 1945, one week before the formal German surrender. The independent states of San Marino and the Vatican, both surrounded by Italian territory, also suffered damage during the conflict.

Even before their victory in the North African campaign during May 1943, the Allies were in disagreement on the best strategy to defeat the Axis. The British, especially Prime Minister Winston Churchill, advocated their traditional naval-based peripheral strategy. Even with a large army, but greater naval power, the traditional British answer against a continental opponent was to fight as part of a coalition and mount small peripheral operations designed to achieve a gradual weakening of the opponent. The USA, with a larger army, favoured a more direct method of fighting the main force of the German army in North-Western Europe, but conceded that the ability to launch such a campaign depended on first winning the 'Battle of the Atlantic'. The strategic disagreement was fierce, with the US service chiefs arguing for the earliest possible invasion of France, while their British counterparts advocated a policy centred on operations in the Mediterranean. There was even pressure from some Latin American countries to stage an invasion of Spain which, under the Falangist leadership of General Francisco Franco y Bahamonde, was friendly to the Axis nations, although not a participant in the war. The US 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, while the British offered the counter-argument that the presence of large numbers of troops trained for amphibious landings in the Mediterranean made a limited-scale invasion possible and useful.

Eventually the US and British political leadership reached a compromise in which both nations would commit most of their forces to an invasion of France early in 1944, but also launch a relatively small-scale campaign in Italy. A contributing factor was President Franklin D. Roosevelt’s desire to keep US troops active in the European theatre during 1943 and his attraction to the idea of eliminating Italy from the war. It was hoped that an invasion might take Italy out of the war, or at least increase the pressure on it and thus weaken it. 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. Italian divisions on occupation and coastal defence duties in the Balkans and France would be withdrawn to defend Italy, while the Germans would have to transfer troops from the Eastern Front to defend Italy and the entire southern coast of France, thus aiding the USSR.

The initial plan for the 'Husky' (i) operation against Sicily was for landings to be made in the south-eastern, southern and north-western areas of the island, which would lead to the rapid capture of key Axis airfields and, with the exception of Messina on the north-eastern corner, all the island’s main ports. This would allow a rapid Allied build-up, as well as denying their use to the Axis. This initial concept was then revised to a reduced number of landings but with more concentration of force.

'Husky' (i) began on 9 July 1943 with both amphibious and airborne landings at the Gulf of Gela. The land forces involved were the US 7^th Army under the command of Lieutenant General George S. Patton, the Canadian 1^st Division and 1^st Armoured Brigade under the command of Major General G. G. Simonds, and the British 8^th Army under the command of Montgomery.

The original plan required a strong advance by the British to the north along the eastern coast to Messina. The Canadians took the central position, with the British on their right and the Americans on the left. The last had the important role of pushing Axis forces out of mainland Sicily on left flank. When the 8^th Army was checked by stubborn defences in the rugged hills to the south of Mt Etna, Patton amplified the US role with a wide advance to the north-west in the direction of Palermo and then directly to the north to cut the northern coastal road. This was followed by an eastward advance in the area to the north of Mt Etna toward Messina, supported by a series of amphibious landings on the northern coast that propelled Patton’s troops into Messina shortly before the first units of the 8^th Army arrived. The defending German and Italian forces were unable to prevent the Allied capture of the island, but succeeded in evacuating most of their troops to the mainland, with the last leaving on 17 August 1943. The Allied forces gained experience in opposed amphibious operations, coalition warfare and large airborne drops.

Forces of the British 8^th Army landed on the 'toe' of Italy on 3 September 1943 in 'Baytown', which was the day on which the Italian government agreed to an armistice with the Allies. The armistice was publicly announced on 8 September by two broadcasts, first by Eisenhower and then in a proclamation by Maresciallo d’Italia Pietro Badoglio, the Italian prime minister. Although the German forces prepared to hold Italy without Italian assistance, only two of their divisions opposite the 8^th Army and one at Salerno were not otherwise committed to the disarmament of the Italian army.

On 9 September, forces of the US 5^th Army, under the command of Lieutenant General Mark W. Clark, who was expecting little resistance, landed against heavy German resistance at Salerno in 'Avalanche', and sat much the same time British forces landed at Taranto in 'Slapstick', which was almost wholly unopposed. There had been a hope that, with the surrender of the Italian government, the Germans would withdraw to the north, since by this time Adolf Hitler had been persuaded that southern Italy possessed no strategic importance. This was not to be, however, for although for a while the 8^th Army was able to make relatively easy progress up the eastern coast of the Italian 'leg', capturing the port of Bari and the important airfields around Foggia. Despite the fast that none of the German reserves in northern Italy having been made available to von Vietinghoff-Scheel’s 10^th Army, it nevertheless came close to repelling the Salerno landing. The main Allied effort in the west was initially centred on the seizure of the port city of Naples, this having been selected as it was the northernmost port that could receive air cover by fighters operating from bases in Sicily. In the city itself, anti-Fascist forces began an uprising, later known as the 'Four Days of Naples', holding out despite continuous German reprisals until the arrival of Allied forces.

As the Allies advanced, they encountered increasingly difficult terrain: the Apennine mountain chain forms a spine along the Italian peninsula offset somewhat to the east. In the most mountainous areas of Abruzzo, more than half the width of the peninsula comprises crests and peaks over 2,950 ft (900 m) which are relatively easy to defend; and the spine’s spurs and re-entrants confronted the Allies with a succession of east/west ridges and rivers across their line of advance. The rivers were subject to sudden and unexpected flooding, which had the potential to thwart the Allied commanders' plans.

Early in October 1943, Hitler was persuaded by Generalfeldmarschall Albert Kesselring, commander of Heeresgruppe 'C' in southern Italy, that the defence of Italy should be conducted as far away from Germany as possible. This would make the most of the natural defensive geography of central Italy and deny the Allies the easy capture of a succession of airfields, each one a step 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. Kesselring was then given command of the whole of Italy and immediately ordered the preparation of a series of defensive lines across the country in the region to the south of Rome. Two lines, the 'Volturno-Linie' and the 'Barbara-Linie', were used to delay the Allied advance and thus buy time for the preparation of the most formidable defensive positions, which formed the 'Winter Line', the collective name for the 'Gustav-Linie' and two associated defensive lines to the west of the Apennine mountains: these latter were the 'Bernhardt-Linie' and 'Hitler-Linie', of which the latter had been renamed as the the 'Senger-Linie' by 23 May 1944.

The 'Winter Line' proved a major obstacle to the Allies at the end of 1943, halting the 5^th Army’s advance on the western side of Italy. Although the 'Gustav-Linie' was penetrated on the 8^th Army’s front, on the coast of the Adriatic Sea, 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. The Allies' focus then turned to the western end of the front, where an attack through the Liri river valley was considered to have the best chance of a breakthrough toward Rome, the Italian capital. Landings behind the line at Anzio during 'Shingle', advocated by Churchill, were intended to destabilise the 'Gustav-Linie' defences, but the advocated early thrust inland to cut off the German defences did not occur because of disagreements which Major General John P. Lucas, commander of the US VI Corps, had with the battle plan, and his insistence that his forces were not large enough to accomplish their mission. Lucas entrenched his forces, during which time Kesselring assembled sufficient forces to form a ring around the Allied lodgement. After a month of hard fighting, Lucas was replaced by Major General Lucian K. Truscott, whose forces eventually broke out in 'Buffalo' during May.

It took four major offensives between January and May 1944 before the 'Gustav-Linie' was eventually broken by the combined assault of the 5^th and 8h Armies (including British, US, Canadian, Free French and Free Polish corps) concentrated along an 18.5-mile (30-km) front between Monte Cassino and the western seaboard. In a concurrent action, Clark was ordered to have the VI Corps break out of the stagnant position at Anzio and cash in on the opportunity to link with the Canadians and thereby cut off and destroy a large part of the 10^th Army retreating from the 'Gustav-Linie'. But this opportunity was lost when on the brink of success, when Clark disobeyed his orders and sent his US forces to enter Rome, which had been declared an open city by the Germans, so no resistance was encountered.

The US forces took possession of Rome on 4 June 1944, allowing the 10^th Army to get away: the evolution of the situation in the next few weeks may have been responsible for doubling the Allied casualties in the next few months. Clark was hailed as a hero in the USA, but post-war assessments have been critical of his command decisions.

Following the capture of Rome, and the Allied 'Overlord' invasion of Normandy in June, the US VI Corps and the Corps Expéditionnaire Français, which together amounted to seven divisions, were extracted from Italy during the summer of 1944 to participate in the Allies' 'Dragoon' invasion of southern France. The sudden removal of these experienced units from the Italian front was only partially offset by the gradual arrival of three divisions, the Brazilian 1^st Division and US 92^nd Division in the second half of 1944, and the US 10^th Mountain Division in January 1945.

In the period from June to August 1944, the Allies advanced beyond Rome, taking Florence and closing on the 'Gotisch-Linie'. This last major defensive line extended from the wester coast, some 30 miles (50 km) to the north of Pisa, along the jagged Apennine mountain chain between Florence and Bologna to the Adriatic coast just to the south of Rimini. In order to shorten the Allied lines of communication for the advance into northern Italy, Generał dywizji Władysław Anders’s Polish II Corps advanced towards the port of Ancona and, after a month-long battle, succeeded in capturing it on 18 July.

During 'Olive', which began on 25 August, the 'Gotisch-Linie' defences were penetrated on both the 5^th and 8^th Army fronts, but there was no decisive breakthrough. Churchill had hoped that a major advance late in 1944 would open the way for the Allied armies to advance to the north-east through the 'Ljubljana gap' (the area between Venice and Vienna) to Vienna and Hungary and thus forestall the Soviet advance into central Europe. Churchill’s proposal had been strongly opposed by the US Chiefs-of-Staff as, despite its importance to British postwar interests in the region, they did not believe that it aligned with overall Allied war priorities.

On 3 November, Lieutenant General Sir Richard McCreery succeeded Lieutenant General Sir Oliver Leese, successor to Montgomery as the commander of the 8^th Army from 29 December 1943. On 16 December 1944, Clark, the 5^th Army commander, was appointed to head the 15^th Army Group, thereby succeeding the Field Marshal the Hon. Sir Harold Alexander as commander of all Allied ground troops in Italy. Alexander succeeded Field Marshal Sir Henry Maitland Wilson as the Supreme Allied Commander in the Mediterranean Theatre. Clark was succeeded in command of the 5^th Army by Truscott, who had been promoted to lieutenant general on 2 September. In the winter and spring of 1944/45, there was extensive partisan activity in northern Italy. As there were two Italian governments during this period, one on each side of the war, the struggle took on some characteristics of a civil war.

The poor winter weather, which made armoured manoeuvre and the exploitation of overwhelming air superiority impossible, combined with the massive losses suffered to its ranks during the autumn fighting, and the need to transfer some British troops to Greece (as well as the British 5^th Division and Canadian I Corps to North-Western Europe), made it impractical for the Allies to continue their offensive early in 1945. Instead, the Allies adopted a strategy of 'offensive defence' while readying themselves for a final offensive when better weather and ground conditions arrived in the spring.

Late in February and early in March 1945, 'Encore' saw elements of the US IV Corps (Brazilian 1^st Division and the newly arrived US 10^th Mountain Division) battling forward across minefields in the Apennine mountains to align their front with that of the US II Corps on their right. They pushed the German defenders from the commanding high point of Monte Castello and the adjacent Monte Belvedere and Castelnuovo, depriving them of artillery positions that had been commanding the approaches to Bologna since the narrowly failed Allied attempt to take the city in the autumn. Meanwhile, damage to other elements of the transport infrastructure on which they were dependent forced the Axis forces to use sea, canal and river routes for resupply, leading to 'Bowler' against shipping in Venice harbour on 21 March 1945.

The Allies' final offensive began with massive air and artillery bombardments on 9 April 1945. The Allies had 1.5 million men and women deployed in Italy in April 1945, while on 7 April the Axis had 599,404 troops, of whom 439,224 were German and 160,180 Italian. By 18 April, the 8^th Army forces in the east had broken through the Argenta gap and sent armour racing forward in an encircling move to meet the US IV Corps advancing from the Apennine mountains in central Italy and thus trap the remaining defenders of Bologna. On 21 April, Bologna was entered by the Polish 3^rd Division and the Italian Gruppo 'Friuli' (both of the 8^th Army) and by the US 34^th Division (of the 5^th Army). The US 10^th Mountain Division, which had bypassed Bologna, reached the Po river on 22 April and farther to the east, on the 8^th Army’s front, the Indian 8^th Division reached the river on the following day.

By 25 April, the Italian Partisans' Committee of Liberation had declared a general uprising, and on the same day, having crossed the Po river on the right flank, forces of the 8^th Army advanced to the north-north-east in the direction of Venice and Trieste. On the US 5^th Army’s front, divisions drove to the north in the direction of western Austria and to the north-west in the direction of Milan. On the 5^th Army’s left flank, the US 92^nd Division advanced along the coast to Genoa. A rapid advance towards Turin by the Brazilian 1^st Division on their right took the German/Italian Armee 'Ligurien' by surprise, causing its collapse.

Between 26 April and 1 May there were the Battles of Collecchio-Fornovo di Taro, which resulted in the surrender of the German 148^th Division to the Brazilians, who took prisoner about 15,000 Italian and German soldiers, and the end of these battles marked the end of the conflicts in Italy and the end of the Italian Fascist army.

As April 1945 came to an end, Heeresgruppe 'C', retreating on all fronts and having lost most of its fighting strength, was left with little option but surrender. von Vietinghoff-Scheel, who had taken command of the army group on 10 March after Kesselring’s transfer to become the Oberbefehlshaber 'West' on 11 March, signed the instrument of surrender on behalf of the German armies in Italy on 29 April, formally bringing hostilities to an end on 2 May 1945.