May Revolution: The Birth of Local Governance in Buenos Aires

The May Revolution (Spanish: Revolución de Mayo) was a pivotal series of events that unfolded between May 18 and 25, 1810, in Buenos Aires. At the time, the city served as the capital of the Viceroyalty of the Río de la Plata, a vast Spanish colony encompassing territories that now comprise Argentina, Uruguay, Paraguay, Bolivia, and portions of Brazil. This week of political upheaval culminated in the removal of the Spanish Viceroy and the establishment of the first local government, marking a decisive step toward independence.

Key Facts

Black&White portrait of a noble woman — The coronation of Infanta Carlota Joaquina was considered an alternative to revolution

Date: May 18 to 25, 1810.
Location: Buenos Aires, Viceroyalty of the Río de la Plata.
Primary Outcome: Removal of Viceroy Baltasar Hidalgo de Cisneros and the creation of the Primera Junta (First Junta).
Core Driver: The collapse of the Spanish monarchy due to Napoleon's invasion of Spain.
Key Figures: Cornelio Saavedra, Mariano Moreno, and Juan José Castelli.

The Catalyst: Crisis in Spain

The coronation of Carlota Joaquina de Borbón was briefly considered an alternative to the Revolution

The revolution was not an isolated event but a direct reaction to the geopolitical chaos in Europe. In 1808, Napoleon Bonaparte forced King Ferdinand VII of Spain to abdicate, installing Napoleon's brother, Joseph Bonaparte, on the Spanish throne. While a Supreme Central Junta initially resisted the French occupation, they suffered significant losses. By February 1, 1810, French troops had captured Seville and most of Andalusia.

The Supreme Junta eventually retreated to Cádiz, where it dissolved itself and formed the Council of Regency of Spain and the Indies. When news of this collapse reached Buenos Aires via British ships on May 18, it created a power vacuum. The local population questioned the legitimacy of a viceroy appointed by a government that no longer existed.

A king dressed with gold clothing — The rule of Joseph Bonaparte as King of Spain was resisted by Spaniards, and cast doubts on the legitimacy of the Spanish viceroys

Roots of Rebellion: International and National Influences

Map of the Spanish city of Cádiz — Map of Cádiz made during the French siege

International Inspiration

The criollos—people of Spanish descent born in the Americas—were heavily influenced by the United States Declaration of Independence in 1776. The success of the American colonies in establishing a republican government proved that independence from a European monarchy was feasible. Furthermore, Spain's own support for the American patriots against Great Britain inadvertently validated the idea of breaking allegiance to a parent state.

Trumbull's Declaration of Independence portrait — The US Declaration of Independence inspired similar movements in the Spanish colonies in South America

The Prelude in Buenos Aires

Internal tensions had been simmering for years. Following the British invasion of 1806, Santiago de Liniers became a popular hero after reconquering Buenos Aires. In an unprecedented move, the local government deposed the previous Viceroy, Rafael de Sobremonte, for fleeing with the public treasury. This event proved that local institutions could remove a royal appointee, setting a dangerous precedent for the Spanish Crown.

A battle ending with a general surrendering to another — William Carr Beresford surrenders to Santiago de Liniers during the British invasions of the River Plate

Portrait of Santiago de Liniers — Santiago de Liniers ruled as viceroy between 1807 and 1809

Regional Unrest and Legal Justifications

Before the events of May, other regions in the viceroyalty had already attempted to revolt. The Chuquisaca Revolution (May 25, 1809) and the La Paz revolution (July 16, 1809), led by Colonel Pedro Domingo Murillo, were both brutally suppressed by Spanish forces. However, these failures deepened the resentment of criollos toward the peninsulars (Spanish-born officials). During this time, legal theories like the "Syllogism of Chuquisaca" emerged, providing a legal framework to justify self-governance in the absence of a legitimate king.

The May Week and the Open Cabildo

Portrait of a secret revolutionary meeting — Secret meeting of the revolutionaries at the house of Nicolás Rodríguez Peña

As tensions peaked in May 1810, Viceroy Baltasar Hidalgo de Cisneros attempted to maintain the status quo. However, a coalition of criollo lawyers and military officials pushed for an open cabildo—a special meeting of city notables—to determine the future of the colony.

Portrait of Viceroy Baltasar Hidalgo de Cisneros — Baltasar Hidalgo de Cisneros, the last viceroy to rule in Buenos Aires

Engraving of a meeting between Castelli and Cisneros — Juan José Castelli asks Baltasar Hidalgo de Cisneros for an open cabildo

On May 22, the open cabildo convened to discuss the legitimacy of the viceroy. While the Council of Regency in Spain viewed any local junta as insurgent, the delegates in Buenos Aires argued that since the government that appointed Cisneros had fallen, his authority had vanished.

Paper detailing an invitation to the open cabildo — Invitation to the open cabildo of 22 May

Portrait of a debate — An open cabildo discussed the legitimacy of the viceroy and the new local government that replaced him

Initially, to avoid immediate chaos, Cisneros was named president of the new junta. This compromise failed to satisfy the public, leading to widespread unrest. Under intense pressure, Cisneros resigned on May 25, 1810.

Depiction of the events of May 25 — The people gathered in front of the Buenos Aires Cabildo

The Establishment of the Primera Junta

Portrait of Bartolome Mitre — Bartolomé Mitre (1821–1906) authored one of the first historical interpretations of the May Revolution

The resulting government, known as the Primera Junta, consisted of representatives from Buenos Aires and invited delegates from other cities in the viceroyalty. While the junta initially declared loyalty to the captive Ferdinand VII to maintain a veneer of continuity, it functioned as a de facto independent government.

Portrait of Cornelio Saavedra — The proposal of Cornelio Saavedra (1759–1829) received the most votes

Allegoric images of the members of the Primera Junta — Members of the Primera Junta

Portrait of the Primera Junta — The Primera Junta ruled after the revolution

Key members of the junta, such as the influential Mariano Moreno, pushed for more radical changes, while others, like Cornelio Saavedra, favored a more strategic, gradual approach. This internal tension would characterize the early years of the new administration.

Portrait of Mariano Moreno — Mariano Moreno (1778–1811), an influential member of the Primera Junta

Legacy and Historical Impact

The May Revolution triggered a secessionist civil war between regions that accepted the authority of Buenos Aires and those that remained loyal to Spain. Over time, the date of May 25 became a symbol of national identity. While July 9 (the date of the formal Declaration of Independence) was also contested as the primary national day, by 1880, the May Revolution was widely recognized as the birth of the Argentine nation.

Portrait of Ferdinand VII — The revolutionaries of the May Revolution declared loyalty to Ferdinand VII of Spain

Commemorative monument at Plaza de Mayo — The May Pyramid, commemorative monument at Plaza de Mayo

Summary of the May Revolution (1810)
Category	Details
Primary Cause	Napoleon's invasion of Spain and the abdication of Ferdinand VII
Key Event	Open Cabildo of May 22, 1810
Immediate Result	Deposition of Viceroy Baltasar Hidalgo de Cisneros
New Government	The Primera Junta (First Junta)
Long-term Effect	Outbreak of secessionist wars and eventual independence

Frequently Asked Questions

What was the primary cause of the May Revolution?

The primary cause was the political vacuum created when Napoleon Bonaparte invaded Spain and forced King Ferdinand VII to abdicate in favor of Joseph Bonaparte, leaving the Spanish colonies without a recognized legitimate authority.

What is an "open cabildo"?

An open cabildo was a special meeting of the city's notables and citizens, convened to discuss and decide on urgent political matters, such as the legitimacy of the governing viceroy.

Who were the criollos?

Criollos were people of Spanish descent who were born in the Americas. They often felt marginalized by the peninsulars (those born in Spain) who held the highest administrative and political offices.

Did the May Revolution immediately declare independence from Spain?

No. The Primera Junta initially declared loyalty to King Ferdinand VII. The revolution was more about establishing local self-governance (popular sovereignty) than an immediate, formal declaration of total independence.

What was the role of the Primera Junta?

The Primera Junta was the first local government established in Buenos Aires after the removal of the Viceroy. It served as the executive authority that managed the territory and initiated the war against loyalist Spanish forces.