Paraguayan War (War of the Triple Alliance)

The Paraguayan War was fought from 1864 to 1870 between Paraguay on one side and Brazil, Argentina and Uruguay on the other. It is often called the War of the Triple Alliance, after the treaty the three allies signed in 1865. In Brazil it is called the Paraguayan War, and in Paraguay it is often called the Great War (Guerra Grande), or in the Guaraní language Guerra Guasu.

Historians generally describe it as the deadliest war between states in the history of Latin America. It involved hundreds of thousands of soldiers, long sieges, great river battles and some of the first ironclad warships used in South America. For Paraguay the result was a catastrophe: its army was destroyed, much of its population died, its capital was occupied and it lost land it had claimed.

The war took place in a region shaped by great rivers. The Paraná and Paraguay rivers flow south into the Río de la Plata, the wide estuary between Buenos Aires and Montevideo. Whoever controlled these rivers controlled trade for Paraguay, for the Argentine interior, and for the Brazilian province of Mato Grosso, which could be reached most easily by boat through Paraguay.

Paraguay became independent from Spain in 1811. Under the dictator José Gaspar Rodríguez de Francia it closed itself off from its neighbours for decades. His successor Carlos Antonio López opened the country, brought in foreign engineers, built a railway, an iron foundry and shipyards, and strengthened the army. When he died in 1862, his son Francisco Solano López became president. Paraguay was a society in which the state owned much of the land and controlled trade, and most people spoke Guaraní as well as, or instead of, Spanish.

Its neighbours were much larger. Brazil was an empire ruled by Emperor Pedro II, with a huge territory and an economy still based on slavery. Argentina was just emerging from decades of civil wars between Buenos Aires and the provinces, and President Bartolomé Mitre was trying to unify the country. Uruguay, a small country between Brazil and Argentina, was divided between two parties, the Blancos and the Colorados, which often fought each other with help from neighbours.

There were also old border disputes. Paraguay and Brazil disagreed about land in the north, and Paraguay and Argentina about land in the Chaco and in Misiones. Paraguay also wanted free navigation on the rivers so that its trade could reach the sea.

The spark came from Uruguay. In 1864 the Colorado leader Venancio Flores rebelled against Uruguay’s Blanco government. Brazil, which said Brazilian ranchers in Uruguay were being mistreated, supported Flores, and Argentina’s government also favoured him. The Blancos looked to Paraguay for help. Solano López warned Brazil that an invasion of Uruguay would threaten the balance of power in the region. In October 1864 Brazilian troops entered Uruguay anyway.

López responded in November 1864 by seizing the Brazilian steamer Marquês de Olinda on the Paraguay River, and in December his army invaded Mato Grosso. He then asked Argentina for permission to march through its province of Corrientes to reach Brazil and Uruguay. When Mitre refused, Paraguay declared war on Argentina and in April 1865 occupied the city of Corrientes. Meanwhile, Flores had taken power in Uruguay with Brazilian help.

On 1 May 1865 Brazil, Argentina and Uruguay signed the Treaty of the Triple Alliance. It said the allies would not make peace until López was removed from power, and it secretly planned how Paraguay’s disputed borders would be redrawn. When the British government published the secret text in 1866, many people in Latin America and Europe were shocked.

Why López went to war is still debated. Some historians see him as an ambitious ruler who overestimated his army and wanted Paraguay to be a regional power. Others stress that he had real reasons to fear that Brazil and Argentina would dominate Uruguay and then Paraguay. Most agree that all sides made serious miscalculations: López expected help from Uruguay’s Blancos and from anti-Mitre Argentine provinces that never came, and the allies expected a short war.

The first phase (1864–1865) was a Paraguayan offensive. Paraguay took parts of Mato Grosso and marched into Corrientes and southern Brazil. But on 11 June 1865 the Brazilian navy destroyed much of the Paraguayan fleet at the Battle of Riachuelo on the Paraná River, and in September 1865 a Paraguayan army surrounded at Uruguaiana, in southern Brazil, surrendered. From then on Paraguay was on the defensive.

In the second phase (1866–1868) the allies invaded Paraguay. They crossed the Paraná in April 1866 and fought at Tuyutí on 24 May 1866, one of the largest battles ever fought in South America, which ended with heavy Paraguayan losses. But on 22 September 1866 an allied attack on the trenches of Curupayty failed disastrously, with thousands of allied casualties against very few Paraguayan ones. The war then settled into a long stalemate in the swamps around the fortress of Humaitá, which guarded the Paraguay River. Cholera and other diseases killed huge numbers of soldiers on both sides. Mitre left the front to deal with revolts at home, and the Brazilian marshal Luís Alves de Lima e Silva, later Duke of Caxias, took over the allied command.

In February 1868 Brazilian ironclads forced their way past Humaitá, and the fortress was abandoned later that year. In December 1868 Caxias led a campaign, known as the Dezembrada, that destroyed most of the remaining Paraguayan army in battles at Itororó, Avay and Lomas Valentinas. Allied troops occupied the capital, Asunción, in January 1869, and an allied-backed provisional government was set up.

López refused to surrender. He retreated into the hills and forests of the interior with a new army that included many boys, old men and wounded soldiers. The Brazilian command passed to Gaston of Orléans, Count of Eu, Emperor Pedro II’s son-in-law. On 16 August 1869 at Acosta Ñu (Campo Grande), Paraguayan forces made up largely of children and teenagers were overwhelmed. The final phase became a pursuit through the north of Paraguay, until Brazilian troops caught and killed López at Cerro Corá on 1 March 1870.

Paraguay mobilised almost its entire male population. Allied armies were large but drew on very different societies. Brazil raised “Volunteers of the Fatherland” and later used forced recruitment; some enslaved men were freed so that they could serve, sometimes as substitutes for their owners’ sons. Many Brazilian soldiers were Black or of mixed ancestry, and their service later affected debates about slavery in Brazil. In Argentina the war was unpopular in several provinces, and recruits sometimes rebelled or deserted.

For Paraguayan civilians the war was total. The government moved people away from advancing armies, and women, children and the elderly followed the army or were forced to move into the interior, where many died of hunger and disease. Women who followed the army or evacuated with the government were later called residentas; women accused of disloyalty, often relatives of suspected traitors, were sent into internal exile as destinadas, where many died. Women also farmed, made supplies and nursed the wounded.

In 1868, at San Fernando, López became convinced that a conspiracy was forming against him. Hundreds of people, including his own brothers, high officials and foreigners, were tortured and executed after hasty trials. Historians disagree about whether any real conspiracy existed; most see the purges as a sign of the regime’s paranoia under extreme pressure.

Allied troops were also responsible for violence against civilians, especially in the final campaign. Paraguayan tradition remembers, for example, the burning of a field hospital at Piribebuy in August 1869. Details of such events are contested, but there is no doubt that the last year of the war was brutal for the Paraguayan population.

The number of deaths is one of the most debated questions about the war. The main problem is that nobody knows how many people lived in Paraguay in 1864. An old figure of 1.3 million is now rejected. Modern estimates of the pre-war population range from about 300,000 to around 450,000, and a few recent estimates are higher.

Because of this, estimates of Paraguay’s losses vary enormously. The historian Vera Blinn Reber argued in 1988 that Paraguay lost a relatively modest share of its population, roughly 7–18.5 per cent. Thomas Whigham and Barbara Potthast, using a recently rediscovered 1870–71 census, argued in 1999 that Paraguay lost about 60–69 per cent of its population. Other scholars have proposed figures in between, around 40–50 per cent. Most deaths were caused not by battle but by disease, hunger and exhaustion.

Allied losses are also uncertain. Brazil probably lost tens of thousands of men, most from disease; Argentina and Uruguay lost fewer in absolute terms. Overall, deaths in the war are often estimated at somewhere between 150,000 and 300,000 or more, but every figure should be treated as an estimate with wide margins. It is often said that after the war women greatly outnumbered men in Paraguay, though exact ratios are disputed.

Paraguay. The country was occupied by Brazilian and Argentine troops; Brazilian forces stayed until 1876. Paraguay lost land north of the Apa River to Brazil and territory in Misiones and the central Chaco to Argentina. A dispute over part of the Chaco between the Pilcomayo and Verde rivers was sent to arbitration by the U.S. president Rutherford B. Hayes, who in 1878 awarded it to Paraguay; the town of Villa Hayes is named after him. A new constitution was adopted in 1870, but the state was bankrupt. Much public land was sold to foreign and domestic buyers in the following decades, and Paraguay remained one of the poorest countries in the region for a long time.

Brazil. The war was very expensive and increased Brazil’s foreign debt. It also turned the army into a powerful national institution whose officers felt ignored by the imperial politicians. The service of formerly enslaved soldiers and the comparison with other nations strengthened the abolitionist movement; the Law of Free Birth was passed in 1871, and slavery was fully abolished in 1888. In 1889 army officers overthrew the monarchy and proclaimed a republic. Historians debate how directly the war led to these changes, but most see it as an important contributing factor.

Argentina and Uruguay. In Argentina the war helped the national government in Buenos Aires strengthen its authority over the provinces, although it also provoked uprisings. Argentina gained Misiones and Formosa. Uruguay, whose civil conflict had started the chain of events, remained under Colorado governments for many decades. Across the region the war deepened mutual suspicion, and Paraguay and Bolivia later fought the Chaco War (1932–1935) over land left unresolved.

In Paraguay the war is the central national tragedy and a source of pride in resistance. For decades after 1870, López was widely blamed for the disaster. In the early twentieth century nationalist writers, especially Juan E. O’Leary, reinterpreted him as a heroic defender of the nation, and in 1936 a new government officially declared him a national hero. The dictator Alfredo Stroessner (1954–1989) made the cult of López part of state ideology. Paraguay’s Children’s Day is celebrated on 16 August to commemorate the child soldiers of Acosta Ñu, and 1 March, the date of López’s death at Cerro Corá, is a national day of heroes. The survival of the Guaraní language is also often linked in popular memory to the war.

In Brazil the war was long celebrated as a great victory, and the Duke of Caxias became the patron of the Brazilian army. Large academic paintings such as Victor Meirelles’s Naval Battle of Riachuelo and Pedro Américo’s Battle of Avaí celebrated it. Later, critical voices in Brazil questioned the war’s cost and asked whether the allies had committed atrocities against Paraguayan civilians.

In Argentina the war was politically divisive from the start, because many provincial leaders opposed Mitre’s alliance with Brazil. Some Argentine historians later saw the war as a crime against a fellow Spanish-speaking people. The painter Cándido López, who lost his right arm at Curupayty and learned to paint with his left, left a famous series of detailed battle scenes. In Uruguay, where the war began with a civil conflict, it has received less attention in national memory. In recent decades historians and governments across the four countries have worked on shared research and acts of reconciliation.

Official sources include allied military reports, the correspondence of commanders such as Caxias and Mitre, parliamentary debates in Brazil and Argentina, and diplomatic correspondence, including British and U.S. diplomatic reports from Asunción and Buenos Aires. The published text of the Treaty of the Triple Alliance is an essential source for allied war aims. Much Paraguayan state documentation was lost or captured during the war, and part of it was taken to Brazil; the loss of Paraguayan archives makes it harder to study the Paraguayan side.

Paraguay also produced remarkable wartime propaganda. Trench newspapers such as Cabichuí, printed at the front with woodcut illustrations and texts partly in Guaraní, show how the regime presented the war to soldiers. Foreigners who had worked in Paraguay wrote influential accounts: the English engineer George Thompson, who served in López’s army, published The War in Paraguay (1869), and the pharmacist George Frederick Masterman, who was imprisoned during the San Fernando purges, published a hostile memoir in the same year. The British explorer Richard Burton wrote letters from the allied side. These accounts are vivid but coloured by their authors’ experiences and loyalties.

Demographic sources are especially problematic. Pre-war counts were incomplete or unreliable, and the discovery of the 1870–71 census material used by Whigham and Potthast did not end the debate, because historians disagree about how to interpret its coverage and gaps. Photographs, including those produced by the Uruguayan firm Bate & Co., are among the earliest war photographs from South America and show the conditions in camps and battlefields.

The earliest histories reflected the victors’ views: López was depicted as a bloodthirsty tyrant who dragged his people to ruin, and the allies as liberators. In Paraguay, by contrast, nationalist “lopizta” writing from the early twentieth century rehabilitated López as a defender of sovereignty, a view that became official under military governments and Stroessner.

From the 1960s and 1970s a “revisionist” interpretation gained wide popularity in South America. Writers such as the Argentine León Pomer and the Brazilian Júlio José Chiavenato argued that Paraguay had been a self-sufficient, relatively egalitarian state, and that the war was encouraged by British imperialism to open Paraguay to foreign capital; Chiavenato described it as genocide. This thesis spread widely in textbooks and popular culture.

Since the 1990s, historians working in archives in several countries have strongly criticised the British-imperialism thesis. Francisco Doratioto’s Maldita Guerra (2002) and Thomas Whigham’s multi-volume history argued that the war grew mainly out of regional rivalries, state-building in the Río de la Plata, and the decisions of López and allied leaders; they found little evidence that Britain planned or pushed the war. Scholars still debate López’s aims, the character of pre-war Paraguay, allied responsibility for civilian deaths, and whether the term genocide is appropriate for what happened to Paraguay’s population.

Newer research looks at the war through social, gender and cultural history: the experiences of women, Afro-Brazilian soldiers, Indigenous peoples in the Chaco and Mato Grosso, the role of disease, and the way national memories were constructed. The demographic question remains the most visible example of how uncertain evidence allows very different conclusions.