Lieutenant Grenfell continued to serve with Lord Cochrane till, by the surrender of the remainder of the Spanish naval forces, the war in the Pacific was concluded; and in the beginning of 1823 he left Chili, and accompanied Lord Cochrane to Brazil, whose newly emancipated government solicited the aid of that distinguished nobleman to expel the Portuguese forces from its territory and shores. This was effected by Lord Cochrane at the head of the Brazilian squadron, by a series of able manœuvres on the coast of Brazil, extending from Bahia to Pará, during the latter part of 1823, when upwards of one hundred of the enemy’s vessels, and three thousand troops, were sent prisoners into the Brazilian ports; and the Portuguese squadron, of superior force to the Brazilian, was driven with loss and in confusion across the Atlantic.
Lieutenant Grenfell, now promoted to the rank of commander, had the good fortune of terminating the naval campaign, by effecting alone, in a captured brig of war, manned from the flagship, the surrender of the Portuguese force in the city of Pará, and the adhesion of that immense and rich province to the cause of the empire, and rejoined his admiral at Rio de Janeiro in 1824, in a new frigate of 50 guns, which he found in the Port of Pará. In the execution of this service, while quelling an insurrection of the newly subjugated Portuguese, Commander Grenfell received a dangerous wound with a poignard in the back. For these services, Commander Grenfell was subsequently made an officer of the Order of the Southern Cross.
The acknowledgment of the independence of Brazil by Portugal the following year terminated the services of Lord Cochrane, who retired to England. At this period the aggressions of the Argentine Confederation on the Southern frontier of Brazil called the naval forces of the empire to the River Plate, where Captain Grenfell, now promoted to the post rank, proceeded in command of a brig of 18 guns, under the Brazilian Admiral, Baron do Rio da Prata.
The naval forces of Buenos Ayres, very inferior to those of Brazil, were commanded by Admiral William Brown, an Irishman,—one of those singular characters whose indomitable bravery, converting weakness into strength, for a long time baffled all the efforts of the Brazilian Admiral. A decisive action at last occurred off Buenos Ayres, in July 1826, in which Admiral Brown’s ship, with two-thirds of her men killed and wounded, was driven ashore a complete wreck, in front of that city. On this occasion Captain Grenfell, whilst in close action with Admiral Brown, and attacked by a fresh ship of the enemy, had his right arm shattered by a grape-shot as he stood on the hammock-nettings of his brig, encouraging his men to do their duty. Captain Grenfell’s wound was very severe, requiring amputation of the right arm, at the shoulder-joint, which was performed three weeks afterwards at Monte Video. On his partial recovery, he came on leave to England, but returned to the River Plate again in 1828, in command of a corvette, just in time to witness the termination of the war. For his services therein, Captain Grenfell was made a Dignitary of the Order of the Southern Cross, received a pension for the loss of his arm, and other marks of friendship and consideration from H.I.M. Don Pedro I. In 1829, Captain Grenfell married Donna Maria Dolores, second daughter of the late Don Antonio Masini, of the city of Monte Video, by whom he has had a family of six sons and four daughters. In the same year, he was appointed one of the escort of H.I.M. the Empress Amelia and H.M. the late Queen of Portugal, Donna Maria II., in their voyage from Europe to Brazil; and afterwards, in the year 1830, he conveyed the Duchess of Goyaz, a natural daughter of Don Pedro I., from Brazil to Europe, in the Isabel, a frigate of 60 guns.
On the occasion of the Revolution of 1831, and the abdication of Don Pedro I., Captain Grenfell was absent from Brazil, but was recalled again to employment by the Regency in 1835. In 1835, he was sent to the province of Rio Grande de Sul, in command of the naval force on the lakes of that province, then in rebellion against the Imperial Government. Success at first attended the Imperial arms; the rebels in various encounters were driven from their positions on the lakes and rivers; their flotilla captured, and their principal chiefs, with all their artillery, a considerable force of infantry and cavalry, reduced to surrender on the River Jacuhy, in a fruitless attempt to force its passage. In all these operations, the naval force under Captain Grenfell had a principal share, for which services, in 1833, he was promoted to the rank of commodore. The scene, however, soon changed: the loyal forces penetrating into the interior were, in 1837, completely routed by the rebels at Rio Pardo, and Casapava, the president of the province, taken prisoner, and the Imperial authority again restricted to the capital, the port, and the lakes; and both the former were closely besieged, and in great danger of falling into the hands of the rebels. At this critical juncture, the Commodore, through his personal influence with the rebels, originating simply from the humanity with which he had treated the prisoners that on various occasions had fallen into his hands, effected at great personal risk a suspension of arms with the rebel chiefs, with reference to the Imperial Government at Rio de Janeiro, which gained important time, checked the rebel career of success, and saved the province to the empire.
The Imperial Government profited by the opportunity afforded for remedying past errors: troops were poured into the province, a new army was organized, the naval forces were augmented with several steamers, and, at length, in 1842, under the able direction of General the Count of Caxias, the army took the field, routed the rebels in various engagements, and finally, in 1844, effected their complete submission to the Imperial Government. In attention (as expressed in his commission) to the distinguished services rendered with so much intelligence, zeal, and activity in the Province of Rio Grande de San Pedro de Sul, towards the pacification of the same province and integrity of the empire, the Commodore was raised to the rank of Rear-Admiral, and made a Grand Dignitary of the Imperial Order of the Rose; and shortly afterwards received the permission of Her Britannic Majesty to hold his rank, and continue in the service of His Imperial Majesty the Emperor of Brazil.
In the year 1844, Rear-Admiral Grenfell was appointed to command the Imperial squadron in the River Plate, where the contest between Buenos Ayres and Monte Video, affecting the commercial interests of neutral states, called the naval forces of most of the maritime powers to the spot, where he supported with firmness the rights of Brazilian subjects. The following year the Rear Admiral received the most marked proof of the estimation of the Imperial Government, in being appointed to command the squadron that carried their Imperial Majesties to the southern provinces of the empire, and hoisted his flag in the frigate Constitution of 50 guns. With the Imperial squadron, were incorporated Her Britannic Majesty’s ship Grecian, Her Most Faithful Majesty’s ship Don John, and the United States’ ship Raritan. The Rear Admiral had the honour of accompanying their Imperial Majesties during their tour, and in the course thereof received many notable proofs of the estimation and regard of the inhabitants of those provinces, who took this opportunity of shewing their grateful sense of his conduct during the civil war. Shortly after the return of the court to Rio Janeiro the Rear Admiral proceeded in the Constitution to England, with his family, and resigning his naval command at Plymouth, in Sept. 1846, assumed his civil appointment of Consul General of Brazil, in the United Kingdom. In the spring following, he was presented at St. James’s. During the years 1847-48, he built and fitted out at Liverpool, for the Imperial Government, the steam frigate ‘Alfonso.’
In August, 1848, Rear Admiral Grenfell received the thanks of the town of Liverpool, and the gold medal of the Liverpool Seamens Shipwreck Society, for his exertions in saving the lives of the passengers and crew of the emigrant ship Ocean Monarch,[60] burnt off that port, and which was promptly succoured by the Alfonso under Captain Marques Lisboa, then on her trial trip. The following letter from H.R. Highness the Prince de Joinville, who was present, shews the sense H.R. Highness entertained of the Rear-Admiral’s behaviour on that trying occasion.
Claremont, 28 Aôut, 1848.—Monsieur,—J’ai reçu la lettre que vous m’avez fait l’honneur de m’écrire au sujet du sauvetage des passagers de l’Ocean Monarch. Je ne mérite point les éloges que vous voulez bien m’addresser. Passager seulement abord de l’Alfonzo je n’ai été malheureusement que le témoin impuissant de la plus douloureuse des catastrophes, mais j’ai vu tenter les plus noble efforts d’arracher à une mort horrible des femmes et des enfans. Qu’il me soit permis de signaler à la reconnaissance publique les Officiers et l’equipage de l’Alfonzo, le matelot Jerome, et surtout Monsieur l’Admiral Grenfell, dont le noble devouement m’a pénétré d’admiration. Ma femme me charge de vous exprimer toute sa reconnaissance pour les sentimens que vous avez bien voulu lui exprimer. Recevez, Monsieur, l’assurance de ma haute considération.—(Signé) F. d’Orleans.—His Worship the Mayor of Liverpool.
The serious misunderstanding which occurred in 1850 between the governments of Brazil and Buenos Ayres, on the subject of the occupation of the territory of Monte Video by the latter power, induced the Imperial Government to augment its forces by sea and by land; and Rear-Admiral Grenfell was selected to command the squadron in the River Plate; and, leaving England in the beginning of 1851, he hoisted his flag at Rio Janeiro again on board the frigate Constitution, and proceeded with several corvettes and steamers to his destination. The Buenos Ayrean army, under General Oribe, was found cantonned round the city of Monte Video: the Buenos Ayrean flotilla, under Commodore Coe, lay in the inner roads of Buenos Ayres.