Capture of the gunboat Marquês de Olinda

The imprisonment of the steam Marquês de Olinda was a Paraguayan naval action carried out on November 12, 1864, in Potrero-Poña, on the Paraguay River, which consisted of the capture of the Brazilian merchant ship and everyone on board. Solano López ordered the imprisonment as a way of responding to the Brazilian invasion of Uruguay, although there was no declaration of war between Paraguay and Brazil. However, since the time when Carlos Antonio López ruled Paraguay, there was disagreement between countries, albeit in a peaceful manner, on territorial and border issues.[1]

Capture of the gunboat Marquês de Olinda
Part of the Paraguayan War
Date November 12, 1864 Location Paraguay River, Paraguay Result Paraguayans capture the Brazilian ship.
Belligerents
Paraguay	Brazil
Commanders and leaders
Francisco Solano López	none
Strength
1 corvette	1 Steamboat
Casualties and losses
none	captured crew and ship

With the rise of Solano López to power, these disagreements became more aggressive, since he expanded his foreign policy, understanding with Argentine and Uruguayan leaders in order to facilitate their access to the sea by the River Plate. Despite this, there was nothing between the Empire and Paraguay to justify any military action on the part of those involved. However, with the Uruguayan War underway, the Uruguayans tried to pressure López to help them against the Brazilians, by sending agents to persuade him and also to gather information that was relevant to the Uruguayan cause.[1]

One of the agents discovered that the Brazilian steam engine Marquês de Olinda was carrying the newly appointed president of Mato Grosso, in addition to armaments and valuable cargo, and advised López to take the ship. It was a Uruguayan attempt to get Paraguayans to act in order to distract Brazil from its territory. López followed this advice and imprisoned him on the 12th, before he crossed the Paraguayan border. All Brazilian passengers, crew and officers were imprisoned, and most of the latter died of torture, hunger and lack of medical care. Only two officers survived the arrest, being released in 1869.[1]

The capture of the Marquês de Olinda triggered actions that led to the beginning of the Paraguayan War, even though the true origin of the conflict is a cause for divergence among historians. After this event, the vessel was converted into a warship and participated in the actions of the invasion of Mato Grosso and the Naval Battle of Riachuelo. In the latter, the vessel suffered a collision by the Brazilian frigate Amazonas and left it stranded.[1][2]