'Propaganda by deed'
You might be interested in the Sunday Times review of Alex Butterworth's history of anarchism, The World that Never Was: A True Story of Dreamers, Schemers, Anarchists and Secret Agents.
Here is a striking quotation from the review.
The leaders of 19th-century anarchism were wild-bearded agitators who moved through the fog of Europe’s radical underworld, their endless (and sometimes hopeless) schemes for insurrection and assassination motivated by a volatile blend of prophetic passion and political despair. At riotous meetings, activists shouted, “Long live dynamite”, and vowed to follow the “black flag of mourning”, not the red one of revolution.
The anarchists were a disparate and disputatious lot, united only by their refusal to wait for the better world promised by their cousins, the communists. As the Russian anarchist Andrei Zhelyabov put it, “History moves too slowly. It needs a push.” The anarchists called their new terrorist ideology “propaganda by deed”, and even developed a quasi-religious martyrology.