The war's background goes back to the events succeeding the War of South American Independence, where Brazil had become a very influential power in South America, but had a clear enemy, Argentina. The two had continuously been fighting against each other politically over territories such as Paraguay and Uruguay, but Brazil had remained clearly on top through a larger military and population. But Argentina had managed to excel in one category that Brazil often ignored, building up alliances with other nations. The Argentinians had built up a modest alliance with Chile and Paraguay. And each of them being republic's made this political stand-off a philosophical challenge between republicanism and imperialism.
The other main cause of the war was continental mastery, a political belief that every continent should have one premier power to run it politically. France and the United States had already been proven as the masters of their respective continents, but the masters of Asia, Africa and South America were still unclear. The Brazilians had also established themselves in an international alliance lead by France, called the Continental Alliance, consisting of France, the United States, Brazil, the Confederation of the Rhine, Iberia, Denmark-Norway, Ireland, Italy, and Poland. Argentina, meanwhile, was working out an alliance with the resurgent Great Britain, along with Russia, Austria, Prussia, and Sicily.
But the final blow in tensions came when the provincial government of the Brazilian province of Uruguay sent a message to the Argentine Republic, asking for their help in winning independence from Brazil. The Argentinians called up their local alliance and declared war on Brazil on November 12, 1866, and Brazil prepared its army for war.
War in Uruguay
On November 25, the Argentinian army marched into Brazilian Uruguay, taking many undefended border towns, like Salto and Paysandu, before they met any major Brazilian resistance. The Argentinians marched in two tightly packed lines, one to go to capture the provincial capital, Montevideo, and one towards Rivera to stop any Brazilian attempts to retake Uruguay. One major help was in almost every town, the thousands of members of the Uruguayan National Liberation Front, lead by the so-called President of Uruguay (chosen by the Provisional Government of Uruguay), Lorenzo Batlle y Grau, revolted in the streets against Brazilian rule. But meanwhile, the Brazilian army had already marched into Uruguay, and Brazilian Emperor Pedro II called for a counter-revolution by Brazilian citizens and pro-Brazilian Uruguayans.The Brazilian Army first engaged the Argentine at Tacuarembo on December 14, where 5,000 Brazilian soldiers met 2,000 Argentine men of the 14th and 15th Argentine Expeditionary Regiment, men with the job scouting out the countryside to fan out any advancing Brazilians. But the Brazilian's numbers proved the decisive force, resulting in the capture of much of the rebellious north by the army after news of the battle caused the Argentinians to stall in their advance as to consolidate their positions, and to establish supply lines. But the Brazilians stagnated in their advance when 15,000 Brazilians were defeated at the Battle of Guichon by 12,000 Argentinians on January 21. The war entered into a deep stalemate between the Argentinians and Brazilians, both professionally trained, in the west, but the Brazilian Army easily defeated the revolutionaries in the east, and the Liberation Front retreated to south of the Cebollanti River by March 1867.
The Brazilians, however, used the time that neither army could move, to mobilize a larger force than the 80,000 men they had sent to fight the Argentinian invasion. The size of the army rose steadily up to 150,000 by June, when the Brazilians broke through, and beat the Argentinians back on their left flank. From there, the Brazilians also began to build a huge momentum and pushed into rebel-held territory in the south, and surrounding Montevideo on September 24, 1868. The city had become the center of the rebellion, and 200,000 revolutionaries were held up in the city upon the time the Brazilians laid siege to it on September 25. But as the rebel's were poorly trained in battle, as they were in defense, resulting in the Brazilians capturing the city on November 12, ending the Uruguayan Rebellion. And with the south in their hands, the Brazilians flanked the Argentinians in the front of their position, and began to also push in their center. The Argentinian's bulge in the Brazilian province, was pushed back and back, more and more, until the Argentinians were forced to retreat back into Argentina by February 1870.
War in Paraguay
Meanwhile all this was happening, 120,000 men from Paraguay and Chile, in coherence with their alliance with Argentina, declared war on Brazil on July 29, 1867, however, the Brazilians were prepared to make the first move, and on August 12, the Brazilian Army invaded Paraguay. The Brazilians, numbering at around 100,000 marched across the border, capturing most of the city's along it, including Fuerte Olimpo, and Pedro Juan Caballero, by the beginning of September. The allies, however, were able to march to the border faster than the Brazilians were able to push through, and beat them twice on the same day at Puetro La Victoria, and Salto del Guiara. But with their superior numbers being put into force through reinforcements, the Brazilians were able to break the enemy lines, and push through to the countryside.
The Brazilians were unable to create a vital line of supply in the north, as the necessary roads had not been built there, the capture of the vital city and road-point of Pozo Colorado, became necessary for the war in the north. The city was assaulted from two sides, 12,000 from the north, 13,000 from the south, but the city, which the Paraguyans knew was important to the Brazilians, was well defended, and did not easily fall. However, a chaotic climax to the battle came when a lapse in communication caused a 27,000 strong force of Chileans, marching to relieve the city, was shot upon by the defenders, leading them to believe the city had been captured. Ironically, the Chileans broke through into the city, allowing the Brazilians to enter once they defeated the Chileans. This embarrassment scarred the allied morale, and lead to the capture of multiple towns being fought over around the Paraguayan capital, Asunción.
Brazilian forces surrounded Asuncion in November of 1868, and forced the remnants of the Paraguayan army to be held up within the city. The Brazilians also fired on the city from gunboats set into the river besides the city, allowing their artillery to attack the city from all sides, and putting the Paraguayans into an even tougher position. But the greatest threat came from under the city, as Brazilian sappers dug mines under the city's defenses without the Paraguayans even knowing it, they laid mines under the enemy's artillery positions around the walls built in the city. On February 2, 1869, at 7:00 AM, the Brazilian soldiers were awakened by the sound of explosions in the city, where they then were ordered to charge into the city with huge breaches in the enemy's position opened and their artillery positions almost completely destroyed. Over the next two weeks, the Brazilians captured more and more of the city, eventually leading to the city's surrender on February 17, 1869, ending the war in Paraguay.
War in Argentina
With their positions in Paraguay re-established, the Brazilian Army marched into Argentina on December 4, 1870. Forces from Brazil marched around the border, and quickly beat the retreating Argentinian Army back into Buenos Aires, while Brazilian Naval Fusiliers were transported from their ports in southern Uruguay to attack the city by sea. The Brazilians marched into Buenos Aires almost without firing a shot, as the Argentine government had been retreated to Santa Rosa. The Brazilians who captured the city, celebrated in its streets while reinforcements arrived and they resumed their march on February 17, 1871. The Brazilians eventually captured Santa Rosa, and the Argentine government, doing so on March 25, forcing the government to agree to a treaty.
But stubborn resistance still persisted in the north, where the Argentine military believed that a few victories may force a more favorable treaty at the least. But as towns and cities like Salta and Catamarca fell, so did the Argentine resistance, to the point where entire resistance were surrendering. Finally, the remainder of Argentine forces surrendered on May 2, 1871, officially ending the fighting, but a treaty still needed to be signed to officially end the war.
Treaty of Rio de Janeiro and Aftermath
The Treaty of Rio de Janeiro was signed on October 27, 1871 between the warring states, with favor to the winning state, Brazil. The terms of the treaty were as followed:
- Chile, Argentina, and Paraguay shall renounce their recognition of the Provisional Government of Uruguay.
- Paraguay shall be annexed to Brazil, and the Republic of Paraguay shall cease to exist.
- All Argentine territory up to the Parana River shall be ceded to the Empire of Brazil.
The war had given South America one true ruler, Brazil, but only for a time, as a new threat loomed north, with Colombia growing an alliance with Peru and Venezuela. But once again a war had proven the power of the idea of continental mastery, and more wars would soon be fought to prove who these were for each continent.