World War II: Benito Mussolini is forced out of office by the King (encouraged by the Grand Council of Fascism) and is replaced by Pietro Badoglio.

World War II or the Second World War was a global conflict between two coalitions: the Allies and the Axis powers. Nearly all of the world's countries participated, with many nations mobilising all resources in pursuit of total war. Tanks and aircraft played major roles, enabling the strategic bombing of cities and delivery of the first and only nuclear weapons ever used in war. World War II is the deadliest conflict in history, causing the death of 70 to 85 million people, more than half of whom were civilians. Millions died in genocides, including the Holocaust, and by massacres, starvation, and disease. After the Allied victory, Germany, Austria, Japan, and Korea were occupied, and German and Japanese leaders were tried for war crimes.

Benito Amilcare Andrea Mussolini was an Italian politician and journalist who, upon assuming office as Prime Minister, became the dictator of Fascist Italy from the March on Rome in 1922 until his overthrow in 1943. He was also Duce of Italian fascism upon the establishment of the Italian Fasces of Combat in 1919, and held the title until his summary execution in 1945. He founded and led the National Fascist Party (PNF). As a dictator and founder of fascism, Mussolini inspired the international spread of fascism during the interwar period.

The Fall of the Fascist regime in Italy, also known in Italy as 25 Luglio, came as a result of parallel plots led respectively by Count Dino Grandi and King Victor Emmanuel III during the spring and summer of 1943, culminating with a successful vote of no confidence against the Prime Minister Benito Mussolini at the meeting of the Grand Council of Fascism on 24–25 July 1943. The vote, although significant, had no de jure value, since by law in the Italian constitutional monarchy the prime minister was responsible for his actions only to the king, who was the only one who could dismiss him. As a result, a new government was established, putting an end to the 21 years of Fascist rule in the Kingdom of Italy, and Mussolini was placed under arrest.