O'Connor, Francis Burdett (1791–1871), general in the Bolivian army, was born 12 June 1791 in Cork city, son of Roger O'Connor (qv), landowner and United Irishman, and his second wife, Wilhelmina, daughter of Nicholas Bowen of Bowenscourt, Co. Cork. Roger and his brother, Arthur O'Connor (qv), MP, were noted political radicals and were in constant conflict with their staunchly loyalist brothers. Roger was also notorious for his eccentricities, which, together with his politics, were carried on to the next generation – Francis's younger brother was the chartist Feargus O'Connor (qv), who ended his life insane. Francis – named for his godfather, the English radical Sir Francis Burdett – was less politically extreme, but his devotion to overthrowing Spanish imperialism in South America was in the family tradition.
After Roger O'Connor was arrested in 1798 and interned for four years, his children remained in Cork in the care of their mother and under the guardianship of Burdett. On his release, Roger settled his family in Castle Dangan, near Trim, Co. Meath, the former home of the Wellesleys. In his autobiography Francis refers to seventeen years’ study in French classical schools and military colleges. This seems exaggerated, but he may have spent time in France, where his uncle Arthur had been made a general by Napoleon. He was certainly home when tragedy struck the family at Christmas 1808/9 – a fire broke out which reduced Castle Dangan to a shell and led to the death of his mother. Her husband came under suspicion of arson as he had recently insured the castle for £10,000, but in his autobiography Francis claims to have inadvertently started the fire himself. Their father's increasing eccentricity – he took up with a young peasant girl and was accused of robbing the Galway mail – helped to force his sons from home. In 1815 Francis set out to join Napoleon (recently escaped from Elba) but was dissuaded by his godfather in London and sent back to Dangan. Three years later his departure was more successful: through a neighbour and former United Irishman, William Aylmer (qv), he obtained a commission from John Devereux (qv) as second-in-command of the regiment of Lancers of the Irish Legion raised to fight for South American independence. Francis set sail on 17 July 1818 and never returned to Ireland.
Soon after arrival in Venezuela he was made lieutenant colonel of the Lancers, which in March 1819 left for battle in Santa Marta (in latter-day Colombia). This town was finally occupied at the end of 1820. O'Connor remained as chief of staff of the province of Santa Marta and helped besiege the town of Cartagena, which fell to patriot forces in October 1821. A month later the republic of Colombia was declared and O'Connor spent the next two years in Panama, trying to raise a local battalion. He demanded a more active assignment and in October 1823 was sent with his battalion to join Bolívar in Peru. For the next 15 months he played a prominent part in the Peruvian campaign and was Bolívar's assistant chief of staff at the battle of Junin (6 August 1824), remarkable as a cavalry encounter in which not a single shot was fired. For political reasons he was briefly replaced as chief of staff at the decisive battle of Ayacucho (9 December 1824). He felt bitter about being set aside, but was soon reinstated and took a decisive part, under Marshal Sucre, in liberating upper Peru from the remaining Spaniards. This area then became the new republic of Bolivia and O'Connor was based there for the rest of his life, being promoted brigadier-general (1831) and major-general (1837). His duties involved defending Bolivia at different times against Argentina, Chile, and Peru, and founding a suitable port for the new republic in 1833.
From about 1826 he settled in Tarija, on the border with Argentina, and served as military governor, as well as managing a large estate with his wife, Francisca Ruybola (m. 23 May 1827) who was twenty years younger than himself. Among his self-appointed tasks was attracting settlers to the province – in June 1827 he published a proclamation encouraging ‘Men of Ireland’ to settle in the ‘New Erin’ of Tarija, where they would be absolute masters of their own destiny. His early influences remained strong – he was patriotic (towards Bolivia and Ireland) and valued independence and self-sufficiency. A staunch protectionist, he was particularly incensed by the prevalence of British textiles in Tarija. Early in his ranching years he showed some of his father's anticlericalism – as military governor he closed all the religious houses of Tarija in 1826, except that of the Franciscans – but he was later a regular mass-goer, and in the last week of his life insisted on rising from his sickbed to walk to church to receive communion because he did not think it right that the priest come to him.
Although he was prosperous, and was sufficiently appreciated by the government to be awarded 5,000 pesos in 1826 as a ‘liberator’, to have a division within the Bolivian army named for him, and to be offered the position of Bolivian minister plenipotentiary to England in 1836 (he refused the post), O'Connor was sensitive to slights and complained in his diary in 1849 that he was ‘a man forgotten by all . . . reduced to seeking my own subsistence at an age – 58 years – when there is little strength left in the body, and even less energy’ (Diary, 6 Aug. 1849; Dunkerley, 164). Nevertheless he found enough energy to live another twenty-two years, rising early every morning and riding up to the last day of his life. He died 5 October 1871 in Tarija. Only one daughter survived infancy. She married Adhemar d'Arlach and her sons added their grandfather's name to their own. O'Connor d'Arlach survives as a surname in southern Bolivia.
O'Connor's was a long, hardworking, spartan life. A biographer estimates that he spent ‘some twenty-four hours in direct combat, three weeks within an hour's ride of enemy forces, seven years in military campaigning and forty-five years farming’ (Dunkerley, 155). A brave, intelligent, and loyal soldier, he was highly praised by, among others, Devereux and Bolívar. On retiring from military life he became an upstanding Bolivian rancher who always spoke and wrote in Spanish. Like other members of his family, he had literary interests, though he published no book in his lifetime. A draft essay on the political economy of Bolivia, written in 1827, greatly resembled his uncle's seminal republican pamphlet The state of Ireland (1798). His other works were his diary, which he kept from 1849, diligently recording the weather, his health, and his business transactions; and his memoirs, which end in 1839. These were edited and published posthumously as the Recuerdos de Francisco Burdett O'Connor (1895).