Canzi was born in Piacenza on 14 March 1893, fought in the First World War, and joined the Italian anarchist movement in the 1920s. He helped train the Arditti del Popolo (People's Commmandos) who fought against Mussolini's Blackshirts. In exile, he agitated against fascism and fought it in the Spanish Civil War. Captured by the Germans in 1940, interned in Italy, he escaped to play a major part in the partisan struggle in his native Piacenza.