The 1919 Bombing of the Avanti! Victory Procession was a political attack in Milan in which Albino Volpi threw a Thévenot grenade at socialist marchers celebrating an electoral victory. The explosion scattered the procession and turned a public demonstration into a test of the armed networks operating around the fascist movement. The subsequent police raids uncovered weapons at the Arditi Association and fascist headquarters, and Benito Mussolini was held briefly at San Vittore Prison before being released the next day.

Setting and Approach

The march was passing along Via San Damiano toward Avanti! headquarters, where a rally was to take place. Thousands of people, including men, women, and children, moved through the streets with flags and songs. Volpi watched from the Bridge of the Sirenette, apart from the crowd. He carried two Thévenot grenades and a dagger; the narrative describes him as having reached the bridge by crossing the wall of Palazzo Visconti and passing through its garden, a route that took about five minutes and avoided notice from the Arditi headquarters on Via Cerva.

The account places the attack within the stark political divide surrounding the procession. Volpi saw the socialist marchers as a disorderly mass and their internationalist song as alien to Italy. This is his hostile perspective, not a neutral description of the demonstrators: the procession itself is also presented as a crowd of workers and families gathered to celebrate and to express hopes for a better life. The contrast between the marchers’ collective, festive movement and the lone armed observer on the bridge gives the attack its immediate tension.

The Attack

Volpi removed the safety pin from one grenade and threw it toward the procession. The device followed an arc into the crowd and exploded; the singing stopped, people screamed, and the marchers scattered. The narrative emphasizes the sudden change from public celebration to panic, while offering no reliable count of those killed or injured. Volpi had a second grenade, but the supplied account does not establish that he threw it.

A contemporary report published in Corriere della Sera on November 18 described an unknown assailant throwing an object from the cast-iron bridge toward the front of the procession. It said the object exploded on impact and fragments struck demonstrators at a distance of twenty or thirty yards. In the ensuing panic, some people tried to help the injured while others pursued the attacker, who disappeared into the darkness. The newspaper characterized the act as that of a fanatic and identified the weapon as apparently a Thévenot grenade. Read beside the narrative’s identification of Volpi, the report preserves the uncertainty faced by witnesses and authorities immediately after the attack.

Raids and Arrests

On November 18, police acted on the direction of Prefect Pesce, following a telegram from Prime Minister Francesco Saverio Nitti that called for anyone keeping hand grenades to be treated as a criminal. The first raid targeted the Arditi Association headquarters on Via Cerva. Officers seized SIPE grenades, Thévenot grenades, pistols, daggers, maces, and ammunition boxes. Captain Ferruccio Vecchi, Piero Bolzon, and Edmondo Mazzucato were arrested. Volpi and other veterans suspected of involvement escaped capture by fleeing across rooftops.

Later that day, police searched the fascist headquarters at Via Silvio Pellico 16. A socialist delegation—Claudio Treves, Filippo Turati, Giacinto Menotti Serrati, and Milan’s mayor, Emilio Caldara—had gone to the prefecture to demand that the Arditi be excluded from the city and the Fasci di Combattimento dissolved. At the offices of Il Popolo d’Italia, agents found thirteen new revolvers, 419 cartridges, and a recently used flare gun hidden in a stove. Umberto Pasella, Enzo Ferrari, and Filippo Tommaso Marinetti were arrested on accusations of threatening state security and organizing armed gangs.

Mussolini was taken to San Vittore Prison and placed in cell 40. He remained there for only twenty-four hours. On November 19, after interrogation, he was released following a telephone call from Luigi Albertini to Nitti. Albertini, a senator and the owner and editor of Corriere della Sera, argued that freeing Mussolini would avoid making him a martyr. The brief detention therefore ended not with an extended prosecution in the supplied account, but with intervention by a prominent newspaper proprietor who believed fascism had already been weakened by its electoral defeat.

Political Significance

The episode exposed the proximity of political demonstration and armed action in postwar Milan. The attack was carried out by one man, but the ensuing searches revealed weapons and organizational links at more than one headquarters. The scale of the march and the relative smallness of the attacker did not make the violence politically marginal: a single grenade could interrupt a mass procession, while the state’s response brought fascist offices, Arditi networks, and senior figures into the same investigation.

The events also reveal an unresolved tension in the state’s treatment of these organizations. Police seized weapons and arrested prominent fascists, and socialist representatives demanded that the armed groups be banned. Yet Mussolini’s release followed within a day after Albertini appealed directly to the prime minister. The bombing thus stands both as an assault on a socialist procession and as an early demonstration of how armed political organization, public order, and elite intervention could converge without producing a decisive break between fascism and the institutions of the state.