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 Revolution
Martín de Álzaga began a mutiny to remove Liniers. On January 1, 1809, an open cabildo (an extraordinary meeting of "vecinos", prominent people of the city) chaired by Álzaga demanded the resignation of Liniers and the appointment of a local junta. The Spanish militia and a group of people summoned by the meeting gathered to support the rebellion. A small number of criollos, notably Mariano Moreno, supported the mutiny, but most of them did not. They felt that Álzaga wanted to remove the Viceroy to avoid his political authority while keeping the social differences between criollos and peninsulars unchanged. The riot was quickly routed when criollo militias led by Cornelio Saavedra surrounded the plaza and dispersed the insurgents. As a result of the failed mutiny, the rebel militias were disarmed. This included all peninsular militias, and the power of the criollos increased as a result. The leaders of the plot, with the exception of Moreno, were exiled to Carmen de Patagones. Javier de Elío freed them and gave them political asylum at Montevideo.