Before becoming one of the most famous fascists of the 20th century, Benito Mussolini was a young socialist, but he split with the movement and then rode a wave of anti-socialist violence to power in Italy.

Benito Amilcare Andrea Mussolini’s middle names came from Italian socialists Amilcare Cipriani and Andrea Costa, and his father was a socialist. In his 20s, Mussolini briefly edited a socialist newspaper in Austria-Hungary, then in 1912, when he was around 30, he took over as editor of Avanti! (Forward!), the official daily newspaper of Italy’s Socialist Party.

But a couple of years later the party expelled Mussolini over his support for Italy’s entrance into World War I.

“Mussolini was more of an authoritarian revolutionary than an orthodox Marxist,” says Michael R. Ebner, an associate professor of history in the Maxwell School at Syracuse University, and the author of Ordinary Violence in Mussolini's Italy (Cambridge University Press, 2011). “With the outbreak of World War I, he came to see nationalism and militarism as the keys to revolutionary upheaval. He therefore left behind Marxist economic determinism and pacifism.”

Mussolini might have left the Socialist Party behind, but many Italians embraced it after the war, in part because establishment politicians were ineffective in solving postwar problems, says Ebner, who is also co-editor of _The Politics of Everyday Life in Fascist Italy (_Palgrave Macmillan, 2017).

“After the sacrifices of the war, and the example of the Bolshevik Revolution in 1917, anything seemed possible,” he says, adding that Socialists made huge electoral gains, taking over local governments, which alarmed some middle- and upper-class Italians.

Seeing those gains, Mussolini took on the Socialists by force. In 1919, Mussolini created the Fasci Italiani di Combattimento, (Italian Combat Squads), the precursor to his Fascist Party. This group engaged in violence against Socialists and other enemies. In 1921, he founded the Fascist Party, turning his paramilitary movement into a formal political party. He coined the name of the party based on the Italian word for bundle—fascio—in reference to bundles of rods used in ancient Rome to symbolize strength through unity. The party emphasized national unity—even if it required violence to keep dissenters in check.

“Basically, Mussolini hated the Socialists, and so did the rest of the Fascists,” Ebner said. “One driving force behind Fascist violence was their desire to punish the Socialists for not supporting Italy during the Great War (World War I). The Fascists viewed the Socialists as cowardly traitors, internal enemies, who needed to be eradicated.”

He noted Mussolini’s paramilitary groups that attacked the Socialist Party and labor unions—known as the Blackshirts—were often paid or supplied by wealthy landowners. Fascist squads burned down Communist and Socialist offices as they took over cities.

In 1921 Mussolini was elected to the lower chamber of Italy's parliament, the Chamber of Deputies, and the next year, tens of thousands of armed Fascists marched on Rome, demanding Mussolini be named prime minister. Italy’s King, Victor Emmanuel III, refused to declare a state of emergency and impose martial law. Instead he dissolved the government and asked Mussolini to form a new one. Mussolini became both prime minister and interior minister, the latter post, critically, giving him control over the police.

Before Mussolini became prime minister, Fascist squads had used violence to kill, harm, frighten, and humiliate their enemies. After Mussolini became prime minister in October 1922, the squads were still important, but Mussolini could also then rely on the police to go after enemies like Communists, Socialists and Anarchists.

“Mussolini could therefore mix 'legal' state repression with 'illegal' squad violence,” Ebner says. “The police found cause to arrest and harass left-wing political opponents, while the squads could engage in beatings and assassinations to silence other critics.”

In June 1924, assassins with ties to Mussolini killed socialist leader Giacomo Matteotti, prompting opposition deputies to boycott the Parliament. On January 3, 1925, Mussolini essentially took responsibility for that assassination in a speech to Parliament that is seen as the start of his Fascist dictatorship.

“I declare before this Chamber, before the world and before God that I personally assume the whole political, moral and historical responsibility for what has occurred,” he told the Chamber. “I declare that if the Fascists are an association of malefactors, then I am the head of that association of malefactors.”

In response to what he called “scandalous” press attacks against Fascism, Mussolini said, “The whole nation is asking what the government is doing, the whole nation is asking whether it is governed by men or by puppets.”

“Standing in his characteristic pose,” the New York Times reported, “with chest well thrust out, thumping the Ministers’ bench with his tightly clenched fist to emphasize his points… he spoke with fire, passion and vehemence … Only force, he said, can decide between Fascism and the Opposition, and this force he now proposes to use.”

Attendees stood and applauded every sentence, and shouted “Vivo Mussolini! Vivo Fascismo!”

“It was the greatest triumph of Mussolini’s whole political career,” the Times said. After his speech, “Deputies rushed at Mussolini from all sides and lifted him shoulder-high carrying him in triumph out of the chamber,” while others danced and sang.

Mussolini, known as “Il Duce” (the Leader), ruled as a dictator from that point on. He fostered a cult of personality, projecting himself as an omnipotent and indispensable leader. His government expelled all opposition, including Socialist members and arrested all Communist members of Parliament. He abolished local elections and reinstated the death penalty for political crimes.

Mussolini's government also required movie houses to show government propaganda newsreels as part of a crackdown on the free press. In “The Doctrine of Fascism,” published in 1932, Mussolini and a fellow Fascist described the state as "all-embracing; outside of it no human or spiritual values can exist, much less have value."

Mussolini allied with German dictator Adolf Hitler in World War II, and ruled Italy until 1943 when he was voted out of power by his own Grand Council and arrested. After German commandos rescued him, he was placed atop a puppet government in German-occupied northern Italy from September 1943 to April 1945.

As the Third Reich lost its grip on northern Italy, Mussolini attempted to flee with his mistress to Switzerland. He wore German clothing and a helmet to try and disguise his identity, but, thanks to his years of promoting his cult of personality, he was quickly recognized. Mussolini was executed along with his mistress by Italian Communist partisans on April 28, 1945.