May Revolution
The May Revolution was a direct reaction to Spain's Peninsular War. In 1808, King Ferdinand VII of Spain abdicated in favor of Napoleon, who granted the throne to his brother, Joseph Bonaparte. A Supreme Central Junta led resistance to Joseph's government and the French occupation of Spain, but eventually suffered a series of reversals that resulted in the Spanish loss of the northern half of the country. On February 1, 1810, French troops took Seville and gained control of most of Andalusia. The Supreme Junta retreated to Cadiz and dissolved itself, and the Council of Regency of Spain and the Indies replaced it. News of these events arrived in Buenos Aires on May 18, brought by British ships.
May Revolution
On May 14, 1810, the British war schooner HMS "Mistletoe" arrived at Buenos Aires with European newspapers that reported the dissolution of the Supreme Central Junta the previous January. The city of Seville had been invaded by French armies, which were already dominating most of the Iberian Peninsula. The newspapers reported that some of the former members of the Junta had taken refuge on the Isla de León in Cadiz. This was confirmed in Buenos Aires on May 17, when the British frigate HMS "John Paris" arrived in Montevideo; the most recent newspapers reported that members of the Supreme Central Junta had been dismissed. The Council of Regency of Cadiz was not seen as a successor of the Spanish resistance but as an attempt to restore absolutism in Spain. The Supreme Central Junta was seen as sympathetic to the new ideas. South American patriots feared both a complete French victory in the peninsula and an absolutist restoration. Cisneros monitored the British warships and seized their newspapers, to conceal the news, but a newspaper came into the hands of Belgrano and Castelli. They spread the news among other patriots and challenged the legitimacy of the Viceroy, who had been appointed by the fallen junta. When Cornelio Saavedra, head of the regiment of Patricians, was informed of this news, he decided that it was finally the ideal time to take action against Cisneros. Martín Rodríguez proposed to overthrow the Viceroy by force, but Castelli and Saavedra rejected this idea and proposed the convening of an open cabildo.