At this point, a brief glance at conditions in Europe is necessary. The alliance between Spain and France, made in 1795, lasted until 1808, when Spain joined England in the effort to crush Napoleón. Napoleón thereupon took his armies into Spain and completely conquered it with the single exception of the city of Cádiz which held out under the protection of the guns of the British fleet. In the same year, King Charles IV abdicated in favor of his son Ferdinand VII, who unhappily was promptly captured by the French. Napoleón made his brother Joseph, King of Spain, and this improvised monarch sent a messenger to the River Plate inviting submission. It was refused. The legitimate King being captive, a Council was established in Cádiz to govern in his name, but in 1810, the people of Cádiz revolted against the Council, assassinated the Governor, and a Regency composed of reactionaries assumed power to act for Ferdinand VII.
Advices reached Buenos Aires about the middle of May, 1810, that the first act of the Regency had been to revoke the decree of the new Viceroy, Cisneros, which had made Buenos Aires a free port, and had further ordered that the former laws covering monopoly by Spain of all Colonial commerce should be enforced more strictly than ever. "This", says Mitre, "was the echo of decadent Spain, which feared its captive would escape and tried to chain it to abuses by enforcing them".
The news created a profound sensation. On May 18th., the Viceroy issued a rogatory decree, entreating the people to remain loyal to the Mother-country. The Argentine leaders replied that the Government of Spain had lapsed, that orders emanating from the self-appointed Regency in Cádiz were without legal value, that as there was no King there could be no Viceroy, and that therefore it was right and necessary that steps should be taken to arrange for self-government. These ideas were proclaimed throughout the city and were received with general applause. A committee headed by Castelli called on the Viceroy and on the City Council, asking that an expression of public opinion be secured, but met with resistance. The leaders threatened that if the authorities did not convoke the people, they would, and would employ force if necessary. The Viceroy and Council reluctantly consented, and the most influential citizens were summoned to a public meeting to be held on May 22nd. in the Town Hall, now on the west side of the present Plaza Mayo. At this meeting, Bishop Lue declared that "While Spanish troops held an inch of Spain, that inch commanded America, and while a single Spaniard existed in America, he should command the Americans". The session was adjourned to meet on the following day, when it was again adjourned until the 24th. There were intrigues by the Viceroy and his friends, and there were dissentions among the patriot leaders. The meeting on the 24th. was prolonged far into the night, and the public, waiting outside in the cold rain, became impatient. Nothing was decided even after the protracted discussions and on the next morning, May 25, 1810, the sun shining brightly, the Plaza filled with people who went in procession to the Town Hall and presented a written demand signed by numerous citizens, requiring that full governing powers be placed provisionally in the hands of a Committee whose names were given. Refusal was impossible, and the Argentine then and there definitely assumed the rights of self-government.
"The revolution", Mitre remarks, "was effected without bayonets or violence, by pure pressure of public opinion, triumphant on the grounds of reason, law and public welfare; abstaining from persecutions it with dignity removed the chains which had bound the nation and assumed the rights of sovereignty with uprightness and moderation".
The population of the entire Viceroyship in 1810, including negros and tame Indians, is calculated at 800,000, of which 250,000 lived in Buenos Aires, Santa Fe, Entre Ríos, Corrientes and Uruguay, principally close to the rivers. In the same year, the population of the United States was 7,000,000, most of which lived close to the Atlantic seaboard. These figures give an idea of the limited number of people who undertook the foundation of a new State in South America.
Differing local impulses but the same contributory provocation from the Regency in Cádiz caused all the Spanish American Colonies to revolt in the year of 1810. In 1811, a Spanish writer said:—"The germ of the evils produced by wrong policies, the injustices of our Government and the iniquities of the public employees in the Colonies, finally exploded and almost simultaneously". As far back as 1783, the famous Count Aranda had told the King: "Americans will undertake to secure independence as soon as favorable opportunity presents". The opportunity had come, and from Mexico to Patagonia, all Spanish America threw off the yoke of the Mother Country and assumed the prerogatives of free and independent nations.
Perú and Upper Perú, now Bolivia, was the stronghold of Spain in South America. The population all told was about 2,000,000, the Royal forces were numerous and efficient, and what was more important, the Viceroy, Abascal by name, was a very able and loyal Governor. If the revolution in Lima in 1810 had prospered, South America would have obtained its independence at once, but the movement was there suppressed within a few weeks, and South America had to endure disastrous and fratricidal wars for fourteen weary years.
The revolution in Buenos Aires was the most coherent and solidly founded of all similar Spanish American efforts. During the ensuing six years Spain succeeded in regaining its ascendancy everywhere with the single exception of the Argentine, which country was destined to be the focal point from which radiated new and successful struggles to achieve independence.
The first thought of the Argentine leaders was to ensure harmony of action in all the territory within the boundaries of the Viceroyship. The revolution occurred on May 25th. 1810, and in June of that year, an expedition of less than 1,000 men, under the nominal command of Colonel Ocampo, but whose real military chief was Antonio Balcarce, left Buenos Aires to give support to the movement in Upper Perú. General Liniers, the hero of the "Reconquista" in 1806 and of the "Defensa" in 1807, had raised the Royal Standard in Córdoba, but had fled, in company with a few supporters upon the approach of the Balcarce army. He was overtaken, judged by a summary court-martial presided over by Castelli who had adopted the Reign of Terror policy of the French Revolution, and was immediately executed. Balcarce continued northward into Upper Perú, and on November 7, 1810 defeated the Spaniards at Suipacha. This was the first victory of the South American revolution.
In September of that same year, Belgrano departed for Paraguay with an army which likewise numbered less than 1,000 men. After gaining some slight advantages which enabled him to get close to Asunción, he was defeated at Paraguarí and subsequently on March 9, 1811, at Tacuarí, both in Paraguay. Belgrano was a poor general but a great citizen, and though he lost battles, he won the respect of his enemies. After Tacuarí, he reorganized and extricated his army in a way that gave him considerable fame, in addition to which his insidious revolutionary propaganda destroyed local Spanish authority. Belgrano was the real founder of Paraguayan independence.