1762 - Anglo-Portuguese expedition against La Plata
The campaign lasted from August 1762 to January 1763
In mid April 1762, Spain, who had already concluded an alliance with France on August 15 1761 and declared war to Great Britain on January 18 1762, opened hostilities against Portugal, a British ally.
During the summer, a company of British noblemen and merchants came to the conclusion that an attack upon the Province of Buenos Aires in South America, the Spanish capital of La Plata (a semi-autonomous region of the vice-royalty of Peru encompassing today Argentina, Uruguay, Paraguay and Bolivia), might be both useful to the nation and lucrative to the adventurers. They purchased from the Admiralty ships Kingston (60) (which they renamed Lord Clive), and Ambuscade (40). They placed these vessels under the command of Captain Robert McNamara, an officer of the East India Company's marine. Captain William Roberts, for his part commanded the Ambuscade (40).
In July, the 2 British ships left London for Lisbon where they obtained the cooperation of two Portuguese vessels, in which were embarked 500 soldiers.
On August 30, the small squadron left Lisbon and sailed for Rio de Janeiro where it was joined by the Portuguese frigate Nossa Senhora da Gloria (38), 8 transport brigs carrying 600 foot soldiers under the command of Lieutenant-colonel Vasco Fernandes Pinto Alpoin.
On November 20, the Anglo-Portuguese squadron sailed from Rio de Janeiro towards the mouth of the Río de la Plata to attack Buenos Aires and Montevideo. The Portuguese governor of Rio de Janeiro, Gomes Freire Count of Bobadela, suggested to McNamara to disembark in the deep cove of Barragán which had been left unprotected by the Spaniards. On its way the squadron unknowingly encountered the vessels transporting the Portuguese prisoners taken by the Spaniards at Colonia del Sacramento and sent back to Rio de Janeiro. Ignoring the fate of the Portuguese colony, McNamara still planned to land in the cove of Barragán and to march on the city of Buenos Aires.
In December, McNamara's squadron captured a small Spanish vessel off the coast of Montevideo. MacNamara thus learned of the fall of Colonia del Sacramento and decided to sail directly for Buenos Aires. However, MacNamara had no pilot knowing the area (Portuguese river pilots had been captured at Colonia del Sacramento) and could not locate the access channel to Buenos Aires which was surrounded by sand banks. He finally resolved to return to Montevideo. Pedro Antonio de Cevallos y Cortés, the Spanish military governor of La Plata, was then at Colonia del Sacramento and , despite going through a severe attack of malaria, remained at the forefront of the defence. Ignoring where the Anglo-Portugueses would land, he sent part of his troops to Maldonado and Montevideo, keeping only 500 men with him at Colonia del Sacramento and 100 others in the San Gabriel Island.
On January 2 1763, the Anglo-Portuguese squadron appeared in front of Montevideo. MacNamara intent to attack the place.
On January 3, a Portuguese ship arrived from Rio de Janeiro carrying orders for MacNamara. A man on board this ship informed MacNamara that the waters of the harbour of Montevideo were too shallow for his ship and that he should instead try to recapture Colonia del Sacramento, claiming that he well knew its channels. With this new information, MacNamara decided to hold a council of war aboard his flagship. This council resolved to attack Colonia del Sacramento.
On January 4, the Anglo-Portuguese squadron anchored in the channel in front of Colonia del Sacramento. A Spanish naval squadron fleet, under the command of Lieutenant Sarriá stood in front of the place. It consisted of the frigate Victoria (26) and Santa Cruz (Captain Urcullu) and of the aviso San Zenón. At the first sight of McNamara's squadron, this Spanish squadron fled, leaving the place to its fate. Sarriá took refuge in the nearby island of San Gabriel where he abandoned his frigate and landed with his officers, leaving the crew (180 men) on board under the command of the boatswain. Meanwhile, to test the defences of Colonia del Sacramento before launching his main assault, MacNamara made several minor attacks which were all repulsed.
At noon on January 6, the three larger vessels of the Anglo-Portuguese squadron took position at 400 meters from the major fortifications of the place: the Lord Clive (60) in front of the Santa Rita bastion, the Ambuscade (40) in front of the San Pedro Alcántara bastion and the Nossa Senhora da Gloria (38) against the San Miguel bastion. The 3 vessels then opened against the place, the artillery duel lasted for 4 hours. Despite the intense artillery fire (more than 3,000 roundshots and grapeshots), the Spanish troops of Cevallos, barricaded in a low ground, suffered very few casualties from the enemy fire which was aimed too high. Around 4:00 PM, a red roundshot set fire to the Lord Clive (60) who until then had suffered 40 casualties. Due to the fire, there were 272 fatalities on board, including the expedition's commander Captain Robert McNamara killed during the action. Of the 78 survivors who had managed to leave the ship, 62 were captured by the forces of Cevallos. Officers taken prisoner were not granted naval status and were tried and hanged on the spot while sailors were imprisoned. The Ambuscade (40) and the Nossa Senhora da Gloria, who had been seriously damaged and suffered heavy casualties (80 in the British frigate alone) retired to Rio de Janeiro with the rest of the Anglo-Portuguese squadron. Spanish losses amounted to only 4 men in the fort. Cevallos managed to recover some of the artillery of the Lord Clive (60) before the explosion of her powder magazine at about 8:00 PM in the evening. The Spanish threw heavy stones on the wreck of the ship to make sure that the British could not refloat her. At 11:00 PM, the foreman of the Victoria (26) sent a boat to San Gabriel Island to pick up Sarriá. As he approached his frigate, Sarriá heard gunshots and ordered to bring him back to the island.
At dawn on January 7, Sarriá briefly returned on board the Victoria (26) before returning to San Gabriel Island, leaving his officers to collect their luggage. In the afternoon he returned to the frigate and headed a council of war, deciding to abandon his frigate without informing Cevallos of his decision. To prevent her from falling into enemy hands, the frigate was then stranded and Sarría ordered to sink her right away, without saving the artillery, gunpowder, ammunition and other supplies. Despite his orders, the boatswain only opened a few holes to delay the entry of water. When Cevallos was finally informed of the events, he immediately ordered the pilot Zapiola Manuel Joaquin and several sailors to save the frigate.
On January 8, the Victoria (26) was entering the harbour of Colonia del Sacramento when a storm hurled her against rocks. The frigate was unable to cast anchors because they had been thrown overboard by order of Sarría. Cevallos put Sarriá and his officers under arrest.
Now freed of any threat from the Anglo-Portuguese squadron, Cevallos then proceeded to an expedition against Brazil.
In 1766, Sarría was eventually tried for cowardice and acquitted.
Clowes, Wm. Laird: The Royal Navy – A History from the Earliest Time to the Present, Vol. III, Sampson Low, Marston and Company, London: 1898, pp. 250-251
Spanish Wikipedia: Invasión anglo-portuguesa al Río de la Plata (1763)
Wikipedia: First Cevallos expedition