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
At dawn on May 23, the Cabildo informed the population that the Viceroy would end his mandate. The highest authority would be transferred temporarily to the Cabildo until the appointment of a governing junta. Notices were placed at various points throughout the city, which announced the imminent creation of a junta and the summoning of representatives from the provinces. The notices also called for the public to refrain from actions contrary to public policy.