As one of the major Axis powers, Italy entered World War II on 10 June 1940, joining the Battle of France in its later stages. Italian dictator Benito Mussolini did so opportunistically as the Allied powers (chiefly France and the United Kingdom) seemed on the verge of collapse, and he hoped to make territorial gains through minimal fighting. While France surrendered on 22 June 1940, the United Kingdom and its Commonwealth continued to fight far beyond the point Mussolini had thought possible.

Mussolini took Italy to war unprepared, and the armed forces were sent into battle with insufficient resources (reduced by previous wars in Spain, Ethiopia and Albania) and many untrained personnel. A high proportion of the military's equipment was obsolescent, particularly in 1940-41. Italy's first military action, the invasion of France, resulted in only limited gains. This was followed by the capture of British Somaliland and the advance into western Egypt, in both cases against heavily outnumbered opponents. However, Italy subsequently experienced major defeats in North Africa and Greece between November 1940 and February 1941, requiring German intervention in spring 1941 to help resume the offensive. Greece and Yugoslavia were then overrun and occupied, but this sparked major partisan uprisings.

In 1941, British Commonwealth forces captured Italian East Africa. In North Africa, large swathes of Italian Libya and western Egypt changed hands several times between Allied and Axis forces. The war effort was hampered by Mussolini dispersing Italy's military strength across several fronts, including the German-led invasion of the Soviet Union in June 1941. Between autumn 1942 and spring 1943, the Axis suffered a series of heavy battlefield defeats in North Africa and the Eastern Front. The Allied invasion of Sicily in July 1943 brought the fighting onto Italian soil, leading to Mussolini being deposed. In September 1943, Italy signed the armistice of Cassibile with the Allies, just as British and American armies invaded the Italian mainland.

Germany was ready for Italy's defection and invaded central and northern Italy; Mussolini was freed by German troops and installed as leader of the Italian Social Republic, a German puppet state. This sparked the Italian resistance movement against the German occupation and a civil war between pro- and anti-fascist factions. In the south, the Kingdom of Italy became an official Co-belligerent of the Allies when it declared war on Germany on 13 October 1943.

The Allied advance progressed slowly, in part because of the mountainous terrain. Rome was liberated on 4 June 1944. During the Allied 1945 spring offensive, a general partisan insurrection against the Germans troops occurred on April 25, the date celebrated in Italy as liberation day. Mussolini was captured and killed on 28 April by partisans while attempting to flee. Axis forces in Italy surrendered the following day, with hostilities ending on 2 May 1945. A final peace agreement was reached between Italy and the Allies with the Treaty of Paris of 15 September 1947.

Background Imperial ambitions

In 1922, Italy's liberal democracy gave way to the dictatorship of Benito Mussolini. Although Italy was one of the victor nations in World War I, Mussolini's National Fascist Party felt a sense of grievance towards Britain and France on the issue of territorial gains from the conflict. The Fascists, whose paramilitary arm was known as the Blackshirts, also laid claim to parts of France, such as Alpes-Maritimes, Corsica and Savoie, as well as Malta in the British Commonwealth.

Mussolini had ambitions to build "a new Roman Empire", according to Gooch, that spanned the Mediterranean, Africa and the Balkans. In 1935, Italy invaded Ethiopia, whose army was mostly irregular troops with obsolete weapons. During the Spanish Civil War of 1936-39, Mussolini gave considerable aid, including air and ground forces, to Francisco Franco's Nationalists, seizing on an opportunity to install a right-wing dictatorship and potential ally.

However, the expense of those conflicts eroded the finances of Mussolini's state, leaving it in a weak position to face another world war.

Drawing closer to Germany

The Italo-German protocol of 23 October 1936 saw Germany recognise Italy's conquest of Ethiopia and Mussolini accept Hitler's designs on Austria. The treaty opened a path to closer co-operation.

During the negotiation of the Munich Agreement in September 1938, Mussolini backed Hitler, showing Fascist Italy was siding with the Third Reich. On 7 April 1939, weeks after Hitler broke the Munich Agreement and occupied Bohemia and Moravia, Italian forces invaded Albania.

On 22 May 1939, Italy and Germany signed the Pact of Steel in Berlin, joining both countries in a military alliance designed for a "joint war against France and Britain".

Military and Industrial Strength

In 1940, Mussolini's military was understrength and of mixed quality compared to other great powers. The Italian Air Force (Regia Aeronautica) at the outbreak of the war had 3,269 aircraft, but 55% were considered to be combat ineffective. Of the 542 fully operational fighters in June 1940, 70% were obsolescent biplanes, such as the Fiat CR.42 Falco. The Italian Royal Navy (Regia Marina) had several modern battleships and heavy cruisers, but no aircraft carriers.

The Italian Royal Army (Regio Esercito) suffered shortages of much of the equipment that had become commonplace in other armies. Some infantry divisions were unmotorised, others were classed as 'auto transportable' but in reality were only partly motorised. Because it had been assumed the army would often fight in mountainous regions, many tanks were small in order to traverse narrow bridges. The bulk of the army's equipment was obsolescent and a re-organisation in 1938 had cut the number of regiments in an infantry division leaving them weakened. Across the services, training was neglected and many personnel had to learn their skills while in the frontline.

Compared to the other great powers, Italy had a less industrialised and more agrarian economy. Italy and Great Britain had similar sized populations in 194043.8 million for Italy, 47.5 million for Britain. However, in that year British industry manufactured 15,000 aircraft, 1,400 armoured fighting vehicles (AFVs) and 13 million tonnes of steel; compared to 2,100 aircraft, 250 AFVs and 2.1 million tonnes of steel for Italy. Many essential commodities had to be imported, and Italy relied heavily on Germany for coal and Romania for oil. Around 27% of the country's merchant ships were in Allied ports when Mussolini declared war in June 1940, and were immediately impounded.

Outbreak of the Second World War

Non-belligerent status

Nazi Germany's invasion of Poland on 1 September 1939 marked the beginning of World War II. However, Italy initially declared itself a non-belligerent, as it was not ready for war and needed time for further re-arming. In December 1939, the Under-Secretary for War Production, Carlo Favagrossa, submitted estimates to Mussolini that suggested the armed forces might not be fully equipped and ready for a major war until 1945.

Mussolini, while accepting Italy needed more time to re-arm, was dissatisfied with the country's non-belligerent status and wanted a way into the waron 2 September 1939, Count Ciano, the Italian foreign minister and Mussolini's son-in-law, wrote in his diary: "The Duce is convinced of the need to remain neutral, but he is not at all happy. Whenever he can he reverts to the possibility of our action."

Italy enters the war

The exact timing of Italy's entry into the war was greatly influenced by political opportunism, coming at a time when Britain and France were in full retreat during the Battle of France. Mussolini wanted a seat at the peace conference table to make territorial gains, and told the heads of the armed forces on 29 May 1940, he feared if Italy entered the war after Anglo-French resistance had collapsed, the Germans would take the view that Italy had only joined in "when the job was done", and thus would be reluctant to share the spoils with the Italians. The deteriorating situation for the Allies in late May and early June persuaded Mussolini to join the conflict, even though the military were not ready.

On 10 June 1940, as the French government fled Paris for Bordeaux, Mussolini declared war on Britain and France. The Duce famously told the Chief of the Military General Staff, Marshal Badoglio, "I only need a few thousand dead so that I can sit at the peace conference as a man who has fought".

Invasion of France and the occupation

Despite the 10 June 1940 declaration of war, the Italian offensive into southern France only began on 21 June, and quickly stalled, having encountered stronger-than-expected resistance. Italian casualties totalled just over 6,000 (a third of whom were troops hospitalised with frostbite), compared to less than 500 casualties for the French. Italy gained just a small occupation zone. According to historian John Keegan, "Italy played an ignominious and Johnny-come-lately part" in the Battle of France.

The Italian Navy established an Atlantic submarine base, BETASOM, at Bordeaux in the German occupation zone, and a total of 32 submarines operated from there between October 1940 and September 1943compared to the 863 German U-boats that fought in the Battle of the Atlantic. Initially, BETASOM got off to a disappointing start, but their combat record steadily improved, and the fleet went on to sink an estimated 571,815 Gross Register Tonnage of Allied shipping.

In November 1942, the Italian army occupied south-eastern Vichy France and Corsica as part of Case Anton.

North Africa

Invasion of Egypt and Operation Compass

Within a week of Italy's declaration of war on 10 June 1940, the British 11th Hussars had seized Fort Capuzzo in Libya. On 28 June, Marshal Italo Balbo, the Governor-General of Libya, was killed by friendly fire. Mussolini ordered Balbo's replacement, General Rodolfo Graziani, to launch an attack into Egypt. Graziani reported that his forces were not properly equipped, but Mussolini still ordered him to proceed. On 13 September, elements of the 10th Army retook Fort Capuzzo and crossed the border into Egypt. Lightly opposed, they advanced 80 km (50 miles) to Sidi Barrani, then halted and built a series of fortified camps.

The Italians had 200,000 soldiers in Libya, while the British had 63,000 in Egypt. However, neither side could commit their full strength to the front at Sidi Barrani. Libya had only been pacified in 1932, so garrisons were needed around the country to prevent uprisings, plus guard the border with Vichy French Tunisia. The British had to consider the other Italian threat in East Africa, plus internal security in Egypt and Palestine. Graziani committed four infantry divisions (two Italian, two Libyan) and a mobile group (which included tanks) to the Egyptian invasion. Two more Italian infantry divisions followed later. They were opposed by Western Desert Force, commanded by General Richard O'Connor, consisting of two British Commonwealth divisionsone armoured and one infantrytotalling 36,000 men. This force was fully mechanised and contained heavily armoured Matilda II tanks.

With the invasion at a halt, the Commander-in-Chief of British Middle East Command, General Wavell, ordered O'Connor to plan an attack that took "every advantage of the element of surprise". On 8 December 1940, Operation Compass began, which saw Western Desert Force overrun the forts at Sidi Barrani, sending the Italians into a full retreat. The Italian anti-tank guns were ineffective against the Matilda II tanks, which inflicted heavy losses. The British reached Beda Fomm on 6 February 1941, enveloping 10th Army, which surrendered the following day. The British took 130,000 prisoners, including 22 generals and an admiral.