May Day - International Workers' Day
- 1886 - The Melbourne Anarchist Club was founded.
- 1909 - Argentinian police shot at a demonstration by the Argentine Regional Workers' Federation, killing several activists.
- 1923 - Japanese anarchist Sakae Osugi was arrested while he was delivering a May Day speech in Paris.
- 1936 - The fourth congress of the Confederación Nacional del Trabajo was held in Zaragoza, Spain.
- 1937 - Spanish Civil War: The Maroto Column is militarized into the 89th and 147th Mixed Brigades.
- 1971 - The Angry Brigade bombed a boutique in London, England.
- 2002 - England's Movement Against the Monarchy and other anarchist groups held demonstrations during Queen Elizabeth II's Golden Jubilee.