These are the selected anniversaries for May that appear on the Anarchism portal. The "edit" links edit the portal subpages that are displayed as sections here.

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.

Edit May 1 anniversaries

• 1919 - German anarchist Gustav Landauer was killed in Germany's Stadelheim Prison.
• 1936 - The first issue of the Mujeres Libres magazine appeared.

Edit May 2 anniversaries

• 1849 – Mikhail Bakunin (pictured) participated in the May Uprising in Dresden
• 1928 – Severino Di Giovanni bombed the Italian consulate in Argentina to protest the dictatorship of Benito Mussolini
• 1937 – Spanish Revolution: Catalan police storm the Telefónica exchange in Barcelona, igniting an armed conflict between anarchists and the forces of the Spanish Republic

Edit May 3 anniversaries

• 1886 - Haymarket riot (pictured) in Chicago, Illinois
• 1895 - Premier of French anarchist Jean Grave's journal Les Temps Nouveaux.
• 1919 - China: Protests against the Treaty of Versailles break out in Beijing, leading to a surge in anarchist activity in China.
• 1937 - Spanish Revolution: Federica Montseny and Joan Garcia i Oliver appeal for a ceasefire in Barcelona but many anarchists, including Domingo Ascaso Abadía, are killed in the day's fighting.
• 1970 - The Angry Brigade bombed the US Embassy in London.

Edit May 4 anniversaries

• 1920 - Sacco and Vanzetti are arrested and accused of robbery and murder.
• 1920 - Charles Ange Laisant dies.
• 1937 - Spanish Revolution: The Generalitat de Catalunya is reshuffled, appointing Valeri Mas i Casas as Minister of Economy, Public Services, Health and Social Assistance, but the street fighting in Barcelona continues. Italian anarchist Camillo Berneri is assassinated by members of the PSUC and the police.
• 1982 - The Unabomber's sixth bomb explodes, injuring the secretary of its target.

Edit May 5 anniversaries

• 1916 - Alexander Berkman founded the No Conscription League.

Edit May 6 anniversaries

• 1937 – Spanish Revolution: The Spanish Guardia de Asalto invade Catalonia and put an end to the anarchist rebellion in Barcelona.
• 1996 – Albert Meltzer (b. 1920) dies in Weston-super-Mare, England.

Edit May 7 anniversaries

• 1911 - The anarchist Mexican Liberal Party captured Tijuana.
• 1912 - George Woodcock was born.
• 1916 - Ben Reitman was sentenced to 60 days in jail for advocating birth control.
• 1919 - Vera Zasulich (pictured) died.
• 1930 - Gary Snyder was born.
• 1937 - Spanish Revolution: The Barcelona May Days end, leaving approximately 500 dead and 1,000 injured.
• 1945 – German anarcho-syndicalist Fritz Kater was injured by a dud bazooka shell.
• 1985 - The Unabomber's eighth bomb exploded at Boeing, in Auburn, Washington.

Edit May 8 anniversaries

• 1849 - Mikhail Bakunin was arrested following the May Uprising in Dresden.
• 1877 - Peter Maurin was born.
• 1911 - Mexican Revolution: The First Battle of Tijuana ends in a Magonista victory, with the Mexican Liberal Party capture of Tijuana.
• 1921 - Daniel Berrigan was born.
• 1937 - Solidaridad Obrera denounced yesterday's manifesto by the Friends of Durruti Group.
• 1939 - Spanish anarchist Miguel García was arrested in jailed for 22 months.

Edit May 9 anniversaries

• 1905 - Oscar Wilde's play Salome opened.
• 1968 - Léo Ferré composed his song The Anarchists during the events of May 1968 in France.

Edit May 10 anniversaries

• 1878 - German anarchist Max Hödel attempted to assassinate Wilhelm I (pictured).
• 2011 - Chile: In its first attack, the Antagonic Nuclei of the New Urban Guerrilla leaves an incendiary device at a Banco de Chile branch in Vitacura.

Edit May 11 anniversaries

• 1890 - Italian anarchist Renzo Novatore was born.
• 1926 - The conviction of Sacco and Vanzetti (pictured) was upheld by the Massachusetts Supreme Court.
• 1946 - The Japanese Anarchist Federation was founded in Tokyo.

Edit May 12 anniversaries

• 1912 - São Paulo, Brazil's Ecole Moderne, based on the teaching ideas of Francisco Ferrer, was founded.

Edit May 13 anniversaries

• 1887 - Individualist anarchist Lysander Spooner (pictured) died.
• 1912 - Bonnot Gang member Octave Garnier was killed in a shootout with police.
• 1940 - Emma Goldman died in Toronto, Canada.

Edit May 14 anniversaries

• 1916 - Alexander Berkman published "The Only Hope of Ireland" in an issue of The Blast!

Edit May 15 anniversaries

• 1887 - Brazilian anarchist Maria Lacerda de Moura (pictured) was born.
• 1901 - French anarchist Gustave Lefrançais died.
• 1904 - The United States Supreme Court upheld the deportation of British anarchist John Turner for violation of the Anarchist Exclusion Act.
• 1909 - Mexican anarchist Ricardo Flores Magón was imprisoned for 18 months.
• 1915 - New York City's Modern School moved to Stelton, New Jersey.
• 1933 - Individualist anarchist John Henry Mackay died of a heart attack.

Edit May 16 anniversaries

• 1917 - Thomas Mooney had his execution stayed pending appeal.
• 1940 - Emma Goldman was buried in Waldheim Cemetery, Chicago, Illinois.
• 1968 - Among others, Philip and Daniel Berrigan (pictured) raided a draft board office in Catonsville, Maryland, burning over 600 draft files.

Edit May 17 anniversaries

• 1827 - Josiah Warren (pictured) opened his first Time Store in Cincinnati, Ohio.
• 1917 - In the US, the draft was reinstated, both Emma Goldman and Alexander Berkman spoke at a rally opposing the draft.
• 1972 - Philip Berrigan went to jail for burning draft files.

Edit May 18 anniversaries

• 1897 - After two years, Oscar Wilde (pictured) was released from Reading Prison.
• 1904 - French anarchist Daniel Guérin was born.

Edit May 19 anniversaries

• 1910 - Miyashita Takichi is the first anarchist arrested in what would become the High Treason Incident.
• 1913 - Emma Goldman and Ben Reitman were arrested in San Diego, California, and put on a train out of town after vigilantes surrounded the police station.
• 1945 - Death of German anarcho-syndicalist Fritz Kater

Edit May 20 anniversaries

• 1869 - Hutchins Hapgood was born.
• 1871 - The "Bloody Week" of suppression of the Paris Commune began.
• 1894 - French anarchist Émile Henry (pictured) was executed by guillotine.
• 1894 - Two anarchists were executed for bombing the Gran Teatre del Liceu in Barcelona, Spain, but were later exonerated.
• 1916 - Enrique and Ricardo Flores Magón were arrested in Los Angeles, California.

Edit May 21 anniversaries

• 1894 - The trial of Luigi Galleani for conspiracy began in Genoa, Italy.
• 1901 - Gaetano Bresci (pictured) was found dead in his prison cell.
• 1937 - At a meeting, the Confederación Nacional del Trabajo proposes expelling the members of the Friends of Durruti Group.
• 1939 - Ernst Toller committed suicide by hanging.
• 1942 - Theodore Kaczynski, better known as the Unabomber, was born
• 1970 - A bomb attributed to the Angry Brigade was found at a police station in London.
• 2006 - Mexico: A teachers' strike begins in Oaxaca, igniting a large wave of protests.

Edit May 22 anniversaries

• 1909 - Two people were arrested at a speech by Emma Goldman. (pictured)
• 1998 - The Love and Rage Revolutionary Anarchist Federation dissolved.
• 2008 - Anarchist folk-singer Utah Philips (1935 – 2008) dies.

Edit May 23 anniversaries

• 1921 - The trial of Sacco and Vanzetti began.

Edit May 24 anniversaries

• 1895 - Oscar Wilde was jailed for homosexuality.
• 1901 - The Argentine Regional Workers' Federation was founded at a congress in Buenos Aires.
• 1926 - Jewish anarchist Sholom Schwartzbard assassinated Symon Petliura who he blamed for the deaths of 15 members of his family in Pogroms in Ukraine.
• 1978 - The Unabomber's first bomb injures one at the University of Illinois.

Edit May 25 anniversaries

• 1926 - A motion was filed to retry Sacco and Vanzetti after someone else confessed to the crime.

Edit May 26 anniversaries

• 1936 - Just a month before his death, Alexander Berkman was released from a hospital in France.

Edit May 27 anniversaries

• 1830 - Louise Michel was born.
• 1864 - Zo d'Axa was born.
• 1871 - The Paris Commune was crushed after two months.
• 1897 - Henry Bauer and Carl Nold were released from prison after having been convicted of aiding and abetting Alexander Berkman's attempted assassination of Henry Clay Frick.
• 1897 - Camillo Berneri was born in Lodi, Italy.
• 1909 - A lecture by Emma Goldman was ordered canceled by the Brooklyn Chief of Police.
• 1937 - The headquarters of the Friends of Durruti Group in Barcelona were shut down by the government.
• 1958 - Christian anarchist Ammon Hennacy (pictured) ended a 40-day fast against nuclear weapons.

Edit May 28 anniversaries

• 1897 - Arrival of anarchist couple Rudolf Rocker and Milly Witkop (pictured with others) in the United States, just days before they were forced to leave the country because they refused to get married

Edit May 29 anniversaries

• 1814 – Russian anarchist Mikhail Bakunin (pictured) was born in Pryamukhino, Russian Empire.
• 1925 - China: Anti-imperialist demonstrations break out in the Shanghai International Settlement, leading to an upswing in recruitment by the Chinese Communist Party and a decline in the influence of anarcho-syndicalism in the Shanghai workers' movement.
• 1972 - The trial of the 'Stoke Newington Eight', also known as The Angry Brigade, starts. It is one of the longest criminal trials in British history.

Edit May 30 anniversaries

• 1905 - Anarchist Alexander Farras threw a bomb into a procession led by the French President Émile Loubet and Alfonso XIII of Spain, failing to harm either.
• 1906 - Catalan anarchist Mateu Morral threw a bomb in a bouquet at Alfonso XIII of Spain during his wedding, but Alfoso once again avoided harm.
• 1910 - Emma Goldman and Ben Reitman were struck by a train while driving in Spokane, Washington.
• 1940 - Among others, Rudolf Rocker and Carlo Tresca (pictured) spoke at a memorial for Emma Goldman.
• 1982 - Canadian anarchists Direct Action blew up a BC Hydro power substation.

• Anarchist Timeline (4,500+ entries)
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Edit May 31 anniversaries