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.

Viceroy Cisneros tried to maintain the political status quo, but a group of criollo lawyers and military officials organized an open cabildo (a special meeting of notables of the city) on 22 May to decide the future of the Viceroyalty.

[5][6] Between 1775 and 1783, the American patriots of the Thirteen Colonies waged a war against both the local loyalists and the Kingdom of Great Britain, eventually establishing a republican government in the place of a constitutional monarchy.

[39] A small secret society of criollos, composed of politicians such as Manuel Belgrano and Juan José Castelli, and military leaders such as Antonio Beruti and Hipólito Vieytes, supported this project.

[40][41] Britain, which had a strong influence in the politics of the Portuguese Empire, opposed the project as well: they did not want Spain split into several kingdoms, and considered Carlota Joaquina unable to prevent this.

[51] On 1 January 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.

[69] However, he rejected economist José María Romero's proposal to banish a number of people considered dangerous to the Spanish regime, such as Saavedra, Paso, Vieytes, Castelli and Moreno, among others.

[75] This was confirmed in Buenos Aires on 17 May, when the British ship John Parish arrived in Montevideo; the most recent newspapers reported that members of the Supreme Central Junta had been dismissed.

[85] During these secret meetings, they appointed a representative commission composed of Juan José Castelli and Martín Rodríguez to request that Cisneros convene an open cabildo to decide the future of the Viceroyalty.

[93] He compared the current international situation with that prevailing at the time of the mutiny of Álzaga over a year earlier, pointed out that Spain was now almost entirely under Napoleonic control and that the undefeated Spanish provinces were very small in comparison with the Americas.

[80] Juan Florencio Terrada, commander of the Infantry Grenadiers, joined them, because their barracks were located under Cisneros' window, and his presence would not allow the Viceroy to request military aid to take Castelli and Martín Rodríguez prisoners.

[88] The police chief requested Morante to feign illness and not appear, so that the play could be replaced with Misanthropy and Repentance by the German novelist and playwright August von Kotzebue.

[116] One of the speakers for the first position was the bishop of Buenos Aires, Benito Lue y Riega, leader of the local church, who said: Not only is there no reason to get rid of the Viceroy, but even if no part of Spain remained unsubdued, the Spaniards in America ought to take it back and resume command over it.

[113] Juan José Paso accepted his first point, but argued that the situation in Europe and the possibility that Napoleon's forces could conquer the American colonies demanded an urgent resolution.

[120] He then expounded the "argument of the elder sister", reasoning that Buenos Aires should take the initiative and make the changes deemed necessary and appropriate, on the express condition that the other cities would be invited to comment as soon as possible.

[153] The Cabildo argued that Buenos Aires had no right to break the political system of the viceroyalty without discussing it with the other provinces; French and Chiclana replied that the call for a Congress had already been considered.

[163] Meanwhile, Cisneros dispatched a post rider to Córdoba, Argentina, to warn Santiago de Liniers about what had happened in Buenos Aires and to request military action against the Junta.

[175] Montevideo, which had a historical rivalry with Buenos Aires, opposed the Primera Junta and the Council of Regency declared it the new capital of the Viceroyalty, along with Francisco Javier de Elío as the new Viceroy.

[182] It was dissolved shortly after the June 1811 defeat of the Argentine troops at the Battle of Huaqui, and two successive triumvirates exercised executive power over the United Provinces of the Río de la Plata.

[186] According to historian Félix Luna's Breve historia de los Argentinos (Spanish: Brief history of the Argentines), one of the most important societal consequences of the May Revolution was the shift in the way the people and its rulers related.

[189] Domingo Faustino Sarmiento stated similar views in his Facundo, and noted that cities were more receptive to republican ideas, while rural areas were more resistant to them, which led to the surge of caudillos.

[191] The brief existence of the Viceroyalty of the Río de la Plata, which had lasted barely 38 years, impeded the consolidation of a patriotic feeling and failed to bring a sense of community to all of the population.

[192] Juan Bautista Alberdi sees the May Revolution as one of the early manifestations of the power struggles between the city of Buenos Aires and the provinces—one of the axial conflicts at play in the Argentine civil wars.

[198] Mitre regarded the May Revolution as an iconic expression of political egalitarianism: a conflict between modern freedoms and oppression represented by the Spanish monarchy, and an attempt to establish a national organization on constitutional principles as opposed to the charismatic authority of the caudillos.

[209][210][211][212] The Primera Junta did not pledge allegiance to the Council of Regency, which was still in operation, and in 1810 it still seemed unlikely that Napoleon would be defeated and Ferdinand returned to the throne (which finally happened on 11 December 1813, with the Treaty of Valençay).

[213] The purpose of such a deception would have been to gain time to strengthen the position of the patriotic cause and avoid reactions that may have led to a counter-revolution, by making it appear that monarchical authority was still respected and that no revolution had taken place.

[217] However, Britain's first priority was the war against France in Europe, and as such they could not be publicly seen to support Latin American independence movements or allow the military attention of Spain to be divided onto two different fronts.

[219] These efforts were primarily by handled by Lord Strangford, the British ambassador at the court of Rio de Janeiro; he expressed support for the Junta, but under the condition that "...the behaviour is consistent, and that [the] Capital [is] retained on behalf of Mr. Dn.

[221] Juan Bautista Alberdi and later historians such as Norberto Galasso,[208] Luis Romero and José Carlos Chiaramonte[222] doubted Mitre's interpretation and put forward different ones.

[233] This situation would change with the final defeat of Napoleon and the return of Ferdinand VII to the throne, as he began the Absolutist Restoration and persecuted the supporters of the new libertarian ideas within Spain.