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.
Mutiny of Álzaga
Historian Bartolomé Mitre explained the mutiny of Álzaga and the May Revolution as closely related events, with the former being an antecedent of the later. This approach was rejected by Vicente Fidel López, who described Álzaga as highly pro-Spanish, decided monarchist and keeper of the Spanish integrity against the goals of the Criollos. He interpreted the events as mere domestic policy, a dispute about who was more loyal to the king, and deemed Álzaga as counter-revolutionary for acting against the goals of the factions that would eventually prevail in the May Revolution a year later. Later historians would accept López's version as canonical.