The Río de la Plata, also called the River Plate or La Plata River in English, is the estuary formed by the confluence of the Uruguay River and the Paraná River at Punta Gorda. It empties into the Atlantic Ocean and forms a funnel-shaped indentation on the southeastern coastline of South America. Depending on the geographer, the Río de la Plata may be considered a river, an estuary, a gulf, or a marginal sea. If considered a river, it is the widest in the world, with a maximum width of 220 kilometres (140 mi).
The Paraguayan War, also known as the War of the Triple Alliance, was a South American war that lasted from 1864 to 1870. It was fought between Paraguay and the Triple Alliance of Argentina, the Empire of Brazil, and Uruguay. It was the deadliest and bloodiest inter-state war in Latin American history. Paraguay sustained large casualties, but even the approximate numbers are disputed. Paraguay was forced to cede disputed territory to Argentina and Brazil. The war began in late 1864, as a result of a conflict between Paraguay and Brazil caused by the Uruguayan War. Argentina and Uruguay entered the war against Paraguay in 1865, and it then became known as the "War of the Triple Alliance."
The Battle of Riachuelo was a large and decisive naval battle of the Paraguayan War between Paraguay and the Empire of Brazil. By late 1864, Paraguay had scored a series of victories in the war, but on 11 June 1865, its naval defeat by the Brazilians on the Paraná River began to turn the tide in favor of the allies.
The Battle of Tuyutí was a Paraguayan offensive in the Paraguayan War targeting the Triple Alliance encampment of Tuyutí. It is considered to be the bloodiest battle ever in South America. The result of the battle was an Allied victory, which added to the Paraguayan troubles after the loss of its fleet in the Battle of Riachuelo.
In the Paraguayan War, the Battle of Yatay was fought on August 17, 1865, between the troops of the Triple Alliance and the soldiers of Paraguay near Paso de los Libres, Corrientes, Argentina.
The Cisplatine War was an armed conflict fought in the 1820s between the Empire of Brazil and the United Provinces of the Río de la Plata over control of Brazil's Cisplatina province. It was fought in the aftermath of the United Provinces' and Brazil's independence from Spain and Portugal, respectively, and resulted in the independence of Cisplatina as the Oriental Republic of Uruguay.
The Platine War was fought between the Argentine Confederation and an alliance consisting of the Empire of Brazil, Uruguay, and the Argentine provinces of Entre Ríos and Corrientes, with the participation of the Republic of Paraguay as Brazil's co-belligerent and ally. The war was part of a decades-long dispute between Argentina and Brazil for influence over Uruguay and Paraguay, and hegemony over the Platine region. The conflict took place in Uruguay and northeastern Argentina, and on the Río de la Plata. Uruguay's internal troubles, including the longrunning Uruguayan Civil War, were heavily influential factors leading to the Platine War.
The Armed Forces of the Empire of Brazil were the overall unified military forces of the Empire of Brazil. The Brazilian military was first formed by Emperor Dom Pedro I to defend the new nation against the Portuguese in the Brazilian War of Independence. The Army and Armada were commissioned in 1822 with the objective of defeating and expelling the Portuguese troops from Brazilian soil.
The Uruguayan War was fought between Uruguay's governing Blanco Party and an alliance consisting of the Empire of Brazil and the Uruguayan Colorado Party, covertly supported by Argentina. Since its independence, Uruguay had been ravaged by intermittent struggles between the Colorado and Blanco factions, each attempting to seize and maintain power in turn. The Colorado leader Venancio Flores launched the Liberating Crusade in 1863, an insurrection aimed at toppling Bernardo Berro, who presided over a Colorado–Blanco coalition (fusionist) government. Flores was aided by Argentina, whose president Bartolomé Mitre provided him with supplies, Argentine volunteers and river transport for troops.
The Campaign of the Hills was the last campaign of the Paraguayan War, lasting from July 1869 to the end of the war on March 1, 1870. The Paraguayans were completely defeated by the Allies. Brazilian writer Alfredo d'Escragnolle Taunay, Viscount of Taunay took part in the campaign and later wrote about it. At least 5,000 Paraguayans were killed during this campaign.
The Battle of Paso de Mercedes was fought on 11 August 1865 during the Paraguayan invasion of the Argentine province of Corrientes.
The Second Battle of Tuyutí was fought on 3 November 1867 between the Paraguayan Army and a smaller allied Brazilian-Argentine force. The Paraguayans lost twice as many soldiers as the allies and were defeated.
The Fortress of Humaitá (1854–68), known metaphorically as the Gibraltar of South America, was a Paraguayan military installation near the mouth of the River Paraguay. A strategic site without equal in the region, "a fortress the likes of which had never been seen in South America", it was "the key to Paraguay and the upper rivers". It played a crucial role in the deadliest conflict in the continent's history – the Paraguayan War – of which it was the principal theatre of operations.
The Passage of Humaitá was an operation of riverine warfare during the Paraguayan War − the most lethal in South American history − in which a force of six Imperial Brazilian Navy armoured vessels was ordered to dash past under the guns of the Paraguayan fortress of Humaitá. Some competent neutral observers had considered that the feat was very nearly impossible.
The Imperial Brazilian Navy was the navy created at the time of the independence of the Empire of Brazil from the United Kingdom of Portugal, Brazil and the Algarves. It existed between 1822 and 1889 during the vacancy of the constitutional monarchy.
José Félix Murature (1804-1880) was a commodore of the Argentine Navy and a painter of Italian origin who served in several conflits including the Argentine Civil Wars, the Cisplatine War and the Paraguayan War.
The steam frigate Amazonas was a frigate-type warship that served in the Imperial Brazilian Navy and, for a short period, in the Brazilian Navy after the Proclamation of the Republic in 1889. The frigate was built in the Thomas Wilson Sons & Co. shipyards in Birkenhead and Liverpool, England; it was launched in August 1851. The purchase of this vessel was part of an effort by the Empire of Brazil to obtain more modern ships, due to the country's lag with some foreign powers. Amazonas was commissioned in 1852.
The Corrientes campaign or the Paraguayan invasion of Corrientes was the second campaign of the Paraguayan War. Paraguayan forces occupied the Argentinian city of Corrientes and other towns in Corrientes Province. The campaign occurred at the same time as the Siege of Uruguaiana.
José María Bruguez (1827-1868) was a Paraguayan general during the Paraguayan War. He was one of the most prominent Paraguayan generals of the war, being known for his artillery services during naval engagements of the war. He died during the 1868 San Fernando massacre after President Francisco Solano López accused Bruguez of conspiring against him.
The Montevideo Naval Division or Rio da Prata Naval Division was a Brazilian naval division based at the Port of Montevideo and operating in Uruguay from 1851 to 1878.
Francisco M. Barroso 
José Murature 
José María Bruguez 
12 ships with 60 cannons:
