Diana Theatre bombing

Following World War I, a group of anarcho-individualists formed in Milan. They carried out a series of attacks targeting public officials, industrialists, and establishments in the city centre frequented by Milan's high society and upper-middle class. There was an attempted bomb attack on a reastaurant on 7 September 7 1919 by the anarchist Bruno Filippi, who was killed in the explosion. On 25 June 1920, a hand grenade was thrown through the windows of the Pasticceria Cova, killing an army captain. A second bomb was thrown at the same establishment on 7 August, injuring three.

In October 1920, Errico Malatesta, the leader of the Italian anarchist movement, was arrested and imprisoned in San Vittore. With no trial date being set, on 18 March 18 1921, Malatesta and two other imprisoned anarchists announced a hunger strike. A small group of anarcho-individualists decided to carry out a series of attacks to protest Malatesta's detention, even though he had never supported the concept of propaganda of the deed or dynamite attacks.

The group decided to attack the Diana Theatre [it], a prestigious venue frequented by Milan's bourgeoisie. They hoped to kill the police chief.^[1][2] On the evening of 23 March, 160 nitroglycerin sticks, covered with straw and empty bottles, were placed in a basket. This was then placed near the artists' entrance.

At 10:40 PM, the large audience took their seats. The bomb exploded, shattering the masonry and hitting the front rows of spectators and the orchestra pit. 172 people were injured,^[3] with 21 deaths,^[3][2][4] including 9 musicians.^[1]