The Passage of the Tonelero was a battle fought near the cliff of Acevedo, in the west bank of the Paraná River

Paraná River

The Paraná River is a river in south Central South America, running through Brazil, Paraguay and Argentina for some . It is second in length only to the Amazon River among South American rivers. The name Paraná is an abbreviation of the phrase "para rehe onáva", which comes from the Tupi language...

, Argentina

Argentina

Argentina , officially the Argentine Republic , is the second largest country in South America by land area, after Brazil. It is constituted as a federation of 23 provinces and an autonomous city, Buenos Aires...

, on 17 December 1851, between the Argentine Army commanded by Lucio Norberto Mansilla and Brazilian warships led by John Pascoe Grenfell.

The battle

In 17 December 1851, the Brazilian fleet commanded by Grenfell was near the cliff of Acevedo in the river Paraná, with the intention to break through the Argentine defenses of Tonelero pass. There were eight Brazilian warships: four steam corvette

Corvette

A corvette is a small, maneuverable, lightly armed warship, originally smaller than a frigate and larger than a coastal patrol craft or fast attack craft , although many recent designs resemble frigates in size and role...

s, Dom Pedro, Dom Pedro II, Dom Pedro and Recife, that towed two sailing

Sailing

Sailing is the propulsion of a vehicle and the control of its movement with large foils called sails. By changing the rigging, rudder, and sometimes the keel or centre board, a sailor manages the force of the wind on the sails in order to move the boat relative to its surrounding medium and...

 corvettes, Dona Francisca and União, plus a brig

Brig

A brig is a sailing vessel with two square-rigged masts. During the Age of Sail, brigs were seen as fast and manoeuvrable and were used as both naval warships and merchant vessels. They were especially popular in the 18th and early 19th centuries...

, Calíope. On board Grenfell's flagship, Dom Afonso, were Brigadier General Marques de Sousa

Manuel Marques de Sousa, Count of Porto Alegre

Manuel Marques de Sousa, the Count of Porto Alegre , was a Brazilian military officer, monarchist and politician.-Early years:...

 and the Argentines Colonel Wenceslao Paunero, Lieutenant-Colonel Bartolomé Mitre

Bartolomé Mitre

Bartolomé Mitre Martínez was an Argentine statesman, military figure, and author. He was the President of Argentina from 1862 to 1868.-Life and times:...

 and Lieutenant-Colonel Domingo Faustino Sarmiento

Domingo Faustino Sarmiento

Domingo Faustino Sarmiento was an Argentine activist, intellectual, writer, statesman and the seventh President of Argentina. His writing spanned a wide range of genres and topics, from journalism to autobiography, to political philosophy and history...

. The ships ferried half of the troops that composed the 1st Division of Imperial Infantry. The rest of the division was waiting at Colonia del Sacramento

Colonia del Sacramento

Colonia del Sacramento is a city in southwestern Uruguay, by the Río de la Plata, facing Buenos Aires, Argentina. It is the oldest town in Uruguay and capital of the departamento of Colonia. It has a population of around 22,000.It is renowned for its historic quarter, a World Heritage Site...

.

To oppose the passage, there were 16 cannons and 2,000 soldiers commanded by Lucio Norberto Mansilla, son-in-law of the leader of the Argentine Confederation

Argentine Confederation

The Argentine Confederation is one of the official names of Argentina, according to the Argentine Constitution, Article 35...

, Juan Manuel de Rosas

Juan Manuel de Rosas

Juan Manuel de Rosas , was an argentine militar and politician, who was elected governor of the province of Buenos Aires in 1829 to 1835, and then of the Argentine Confederation from 1835 until 1852...

. For one hour the Argentines fired more than 450 cannon rounds in the direction of the Brazilian ships, causing little damage, but killing four sailors and wounding other five. The warships counterattacked, without causing major damage to the Argentine forces, killing eight soldiers and wounding twenty. The squadron landed the troops at Diamante

Diamante, Entre Ríos

Diamante is a city in the west of the province of Entre Ríos, Argentina, on the eastern shore of the Paraná River. It has about 20,000 inhabitants as per the . It is the head town of the Diamante Department....

, Entre Ríos

Entre Ríos Province

Entre Ríos is a northeastern province of Argentina, located in the Mesopotamia region. It borders the provinces of Buenos Aires , Corrientes and Santa Fe , and Uruguay in the east....

and part of the ships returned to bring the other battalions that stayed behind in Colonia. Mansilla believed that the Brazilian division was going to land right on his main position.
He fled along with his men, leaving all the artillery and other equipment behind.