The Heroína (Spanish for "heroine") was a privately owned frigate that was operated as a privateer under a license issued by the United Provinces of the River Plate (later Argentina). It was under the command of American-born Colonel David Jewett and has become linked with the Argentine claim to sovereignty of the Falkland Islands.
Many modern authors report this letter as the declaration issued by Jewett. The Heroína received Weddell's assistance in obtaining anchorage off of Port Louis, and, Weddell describes how Jewett, "In a few days, he took formal possession of these islands for the patriot government of Buenos Ayres, read a declaration under their colours, planted on a port in ruins, and fired a salute of twenty-one guns." Weddell also linked the ceremony to Jewett's claim to the wreck of the Uranie and that it was calculated to make an impression on the masters of ships in the area. Some ship-masters were alarmed by Jewett's appearance, fearing being robbed or captured and one contemplated an armed response. Weddell was able to convince him Jewett was no danger and after being introduced to Jewett, he overcame his fears.
Weddell left the islands on 20 November 1820 noting that Jewett had not completed repairs to the Heroína. On leaving the Islands, Jewett took the American schooner Rampart as a prize, an incident that had diplomatic repercussions with the United States of America.
In February 1821, Jewett was relieved of command being replaced by Guillermo Roberto Mason. On June 14, 1821 Heroína captured the Spanish brig Maipú, which was incorporated into the flotilla. Mason also attacked and seized the Portuguese ships Viscondesa and Providencia before putting into Gibraltar for repairs.
On 20 March 1822 the Heroína was met by the Portuguese 44-gun frigate Pérola off Gibraltar. The Pérola managed to approach the Heroína and fired a broadside at point-blank range, ravaging the deck on the H
On 20 March 1822 the Heroína was met by the Portuguese 44-gun frigate Pérola off Gibraltar. The Pérola managed to approach the Heroína and fired a broadside at point-blank range, ravaging the deck on the Heroína and forcing Mason to surrender. The Heroína was taken to Lisbon as a prize. For his action the Portuguese commander, captain Marçal de Ataíde Barahona, was made a knight of the Portuguese Military Order of the Tower and of the Sword, of Valour, Loyalty and Merit. The actions of the Heroína in seizing Portuguese ships led to her being labelled as a pirate ship.
Mason was held by Portugal for two years before returning to Buenos Aires.