On June 28, 1914, members of Young Bosnia carried out the assassination of Archduke Franz Ferdinand of Austria, inspired by the anarchist conception of propaganda of the deed. This act of "tyrannicide" triggered a series of events that eventually spiralled into World War I, beginning with the invasion of Serbia by Austria Hungary and their fellow Central Powers. Anarchists organized an anti-militarist resistance in response to the war's outbreak, encouraging people to refuse to do military service. One of the anarchists that refused was Pierre Ramus, who spent most of the war either in prison or under house arrest. The Social Democrats initially supported the Austrian entry into the war, despite having made anti-militarist statements in the past.