Please look at the excellent article Italians in WWII by Justin Demetri
The years from 1940 to 1945 in Italy, as well as in many other countries of the world marked the Second World War. During the Second World War, Italy had a long and varied military history. While the forces of Italy were considered to have poorly performed during the war, this was mainly because of the circumstances at the time. It began in June 1940, when the French government declared Paris as an open city when German armies invaded the country.
At the time, Mussolini had felt that the war would not last very long and he declared a war on France and Britain. Mussolini had the aim of expanding the colonial holdings of Italy in North Africa by taking colonies from France and Britain.
The Attack on France
The Italians launched their first attack on France in June, 1940. After being successful initially, they stalled at the Alpine Line. France surrendered to Germany in the same month and Italy captured a few areas of France along the Italian- French border.
In November of 1942, the Italian armies again invaded southeastern France and Corsica. From the next month Italian military government had been established on the east side of Rhone River. This continued until September when Italy decided to quit the war.
North Africa Campaign
Italy never experienced any achievements in North Africa from the time it began its invasions. Within a week of declaring war in 1940, the British had seized Fort Capuzzo in Libya. During the entire time that Italian troops had been fighting in North Africa, it experienced several set backs and had to ask for help from the German forces.
Battle of Britain
Mussolini, the dictator of Italy had intended on supporting Germany during Battle of Britain. His air force then had been called the Italian Air Corps or the CAI in Italian. The CAI travelled to Belgium in 1940 and first attacked in October 1940. The aircraft had taken part towards the end of the battle.
All of the equipment used by the Italian government, including outdated biplane fighters, could not match to the ones used by Britain or Germany. Due to this, Italy did not gain much success during the battle.
Along with several other well known battles in 1940, the Italians also started their East Africa campaign in June. The front had been opened from their colonies in East Africa: Eritrea, Somaliland and Ethiopia. Like it had been in Egypt, the Italian forces joined hands with the native army and outnumbered the British troops. However, Italian East Africa had been quite far away from the mainland. This resulted in the forces being cut off from their supply. This only resulted in severely limiting the operations in the region.
During the early East Africa attacks, two different methods had been adopted. The direction of Kenya as well as towards Sudan had been used. Later, in August the Italian troops advanced into Somaliland, once owned by the British. After a few casualties, the British troops were evacuated from the region by the Italian forces.
Even before Italy declared war, Mussolini had been taken by Albania and his eyes set on the land. At the beginning of 1939, while the other countries were only focused on Hitler's advances on Czechoslovakia, Italian troops attacked Albania in April 1939. Though there were strong resistances from the natives, Italy was able to quickly take control of Albania.
Invasions of Italy
In July 1943, the British and American troops joined hands and attacked Sicily in an operation known as Operation Husky. The German troops again took to the cause and helped Italy defend the attacks. Though they lost Sicily to the allies, they did succeed in sending a large number of Italian and German forces to safety from Sicily to the mainland.
Later that same month, an air raid in Rome destroyed the civil as well as the military installations and monuments. With these attacks, the support that Italy had been getting in the war from its people soon diminished. In July 1943, the Italian dictator Mussolini had been ousted by the Grand Council of Fascism. The new government which had been led jointly by the popular King, Victor Emmanuel III and Pietro Badoglio then took over Italy.
The Italian government soon began work and stated on negotiations with the allies in secret in order to bring an end to the war. The new government had been interested on being on the side of the allies. Then in September 1943 an armistice had been secretly signed between Italy and the allies at the Fairfield Camp located in Sicily. This had been announced a few days later. By this time the allies were already in mainland Italy.
Winston Churchill had always regarded southern European countries to be quite weak in the continent. During the First World War, he had advocated in favor of the Dardanelles operation and then later in the Second World War he had advocated the Balkans to be the main operation area. Churchill had called Italy the soft underbelly of the continent and had therefore decided to invade the country.
However, Italy did not prove to be an easy target for the forces. Due to the rugged mountain terrain the Italian troops had excellent positions for defense; however, it did ignore the advantage that the allies had in terms of mechanized and motorized weapons and units.
The final victory of the allies over the axis in Italy did not happen until the spring of 1945. This happened when the allies had crossed the Gothic line. This resulted in the German forces, which had been in Italy, to surrender. With the German forces surrendering after all these years, the Second Word War finally ended for Italy.