Triple Alliance, War of the, 1865–70, fought between Paraguay on one side and an alliance of Argentina, Brazil, and Uruguay on the other. Brazil's military reprisals for injuries to Brazilian subjects in Uruguay's civil war brought a declaration of war against Brazil from Francisco Solano López López, Francisco Solano (fränthēs`kō sōlä`nō lō`pās)
..... Click the link for more information. , Paraguayan dictator, who favored the Blanco regime in Uruguay. Imprudently, he also declared war on Argentina after Bartolomé Mitre refused to allow Paraguayan troops to cross Argentine territory. A secret alliance, made by Brazil and Argentina with Gen. Venancio Flores of the Colorado faction (traditional enemies of the Blancos), brought Uruguay into the war. The heroic defense of Paraguay against powerful invaders lasted five years until the final stand at Cerro Corá, where the entire populous rallied around López. By the end of the war Paraguay was devastated and a considerable part of its male population killed. The war was the brutal consequence of López's provocations as well as of the abusive aggressiveness of the larger powers. It nevertheless opened the way for a development of constitutional government in Paraguay.

Triple Alliance, War of the

or Paraguayan War

(1864/65–70) Bloodiest conflict in Latin American history, fought between Paraguay and the allied countries of Argentina, Brazil, and Uruguay. The Paraguayan dictator Francisco Solano López (1827–70), objecting to Brazil's interference in the politics of neighbouring Uruguay, declared war on Brazil in 1864. The next year Argentina organized the Triple Alliance with Brazil and Uruguay. After three years of fighting, the allies annihilated the Paraguayan forces, but Solano López carried on a guerrilla war until he was killed. Paraguay was devastated by the war; its population was reduced by half, and territory covering some 55,000 sq mi (140,000 sq km) was annexed by Brazil and Argentina.