May Revolution
The mutiny of Aranjuez in 1808 led King Charles IV of Spain to abdicate in favor of his son, Ferdinand VII. Charles IV requested that Napoleon restore him to the throne; instead, Napoleon crowned his own brother, Joseph Bonaparte, as the new Spanish King. These events are known as the Abdications of Bayonne. Joseph's coronation was met with severe resistance in Spain, which started the Peninsular War, and the Supreme Central Junta took power in the name of the absent king. This also led to Spain switching allegiances from France to Britain. France eventually invaded Sevilla, and a Council of Regency based in Cadiz replaced the disbanded Supreme Central Junta.
May Day riots of 1894
The riots of 1894, along with the Haymarket Affair, brought about a series of discussions about the workforce in America and the depression. In 1904, the International Socialist Conference meeting in Amsterdam called on "all Social Democratic Party organizations and trade unions of all countries to demonstrate energetically on May First for the legal establishment of the 8-hour day, for the class demands of the proletariat, and for universal peace." The congress made it "mandatory upon the proletarian organizations of all countries to stop work on May 1, wherever it is possible without injury to the workers."