The Paraguayan War -- known as the War of the Triple Alliance -- was the deadliest conflict in South American history. It began in November 1864 when Lopez ordered the seizure of a Brazilian steamer and launched invasions of Brazilian and Argentine territory. The Triple Alliance of Brazil, Argentina, and Uruguay formed in May 1865 to oppose him. Paraguay's offensives failed, and the war became a long, devastating retreat. A naval blockade isolated the country. The Battle of Tuyuti in May 1866, involving 55,000 men, was the largest pitched battle ever fought in South America. By January 1869, allied forces occupied Asuncion. Lopez fled north with his dwindling column. At the Battle of Acosta Nu in August 1869, Paraguayan children fought with sticks and were slaughtered. After that, there was nothing left but the pursuit.

Cerro Cora was a landscape that promised refuge and delivered a trap. Rocky outcrops and dense forest ringed the camp, bordered on three sides by the Aquidaban River and its tributary. One of Lopez's followers called it a "circus of gigantic rocks." Two roads led in: one from the northwest across the Tacuara stream, one from the southeast through Brazilian territory. For a well-supplied garrison, the position might have been defensible. For Lopez's forces -- sick, starving, numbering roughly five hundred against an approaching Brazilian column of 2,600 well-armed men -- it was a dead end. Lopez posted ninety men with two small cannons at the Tacuara crossing and another hundred at the Aquidaban. He sent General Bernardino Caballero across the border into Brazil with 54 men to steal cattle, which meant his best remaining officer and soldiers were absent when the attack came.

On March 1, at six in the morning, Brazilian forces under General Jose Antonio Correia da Camara struck from two directions simultaneously. At the Tacuara stream, Lieutenant Colonel Francisco Antonio Martins attacked from the rear with bayonets, overrunning the position so quickly that the Paraguayan artillery never fired a shot. Information from deserters had told the Brazilians exactly where to strike. The defense at the Aquidaban fell moments later. Lopez sent ten men under Lieutenant Colonel Candido Solis to investigate -- they were massacred on the road. Imperial cavalry poured into Cerro Cora and surrounded the camp in a pincer movement, sabering and spearing whoever they found. General Francisco Roa died fighting at the mouth of the Chiriguelo trail. The assault on the camp itself lasted only minutes before resistance collapsed.

Lopez, accompanied by Colonel Silverio Aveiro and a handful of officers, tried to flee on horseback but was cut off by Brazilian cavalry. When called upon to surrender, he refused. A corporal named Jose Francisco Lacerda -- nicknamed Chico Diabo, Devil Frank -- drove a spear into Lopez from below, fatally piercing his abdomen. Aveiro somehow got the wounded president back onto his horse and into the forest, following the trail left by Lopez's companion Eliza Lynch and their children. Brazilian General Camara found Lopez on the bank of the Aquidaban-nigui stream, lying face down with his body partly in the water, sword still in hand. According to Camara's account, Lopez was summoned to surrender multiple times and replied: "No me rindo, ni entrego mi espada, muero con ella y por mi patria" -- I do not surrender nor deliver my sword; I die with it and for my country. Lopez's fifteen-year-old son Panchito, who had gone back to escort his mother's cart, was ordered to surrender by Brazilian officers. His own mother urged him to comply. He refused, drew his saber, and was shot dead.

With Lopez dead, the war was over -- and so, in many ways, was the country he had led into it. Paraguay lost disputed territories to both Brazil and Argentina. Its population had been decimated in proportions rarely seen outside of plague, and the demographic catastrophe left the nation unable to recover its prewar trajectory for decades. In the camp at Cerro Cora, Brazilian soldiers lost control, killing wounded Paraguayans and setting fire to the encampment. About 240 prisoners were taken; seven Brazilians were wounded. General Caballero, absent during the battle, surrendered with his 54 men on April 8 -- the last Paraguayan soldiers to lay down arms. In the decades that followed, Lopez's legacy was rewritten repeatedly: tyrant, then nationalist hero, then anti-imperialist martyr, then a more complicated figure still. Cerro Cora became a national park -- the place where a country bled its last became the place where Paraguay chose to remember what it had endured.