Devereux (D'Evereux, Devereaux), John (1778?–1860), soldier and adventurer, was born in Co. Wexford, son of a prominent catholic landowner, probably William Devereux of Taghmon, Co. Wexford. He and his father may have been United Irishmen: they certainly took part in the 1798 rebellion, bringing many of their tenants to the rebel army and fighting at the battles of New Ross and Vinegar Hill. A rebel commander described John's conduct at Ross as ‘truly heroic’ (Cloney, 41). After the rebellion he was hidden in Dublin by a Carmelite priest, Fr Francis Joseph L'Estrange, until he emigrated to America under amnesty about December 1799; it may be that the authorities were lenient with him because of his father's intervention on behalf of loyalist prisoners during the rebellion. In 1806 the British government allowed him to return to Ireland for a year, but on arrival in London in 1807 he was refused permission to travel to Wexford, possibly because the authorities had intercepted a letter from Arthur O'Connor (qv) offering him a senior commission in the Irish legion of the French army. He did go to France, but does not appeared to have joined the army, and returned to America after 1815.
He mixed with Latin-American exiles in Baltimore, and in 1817, by exaggerating his influence, managed to have himself appointed envoy to the USA by the government of Buenos Aires. He went to South America to help the colonists in their struggle against Spanish rule, and in 1818 he wrote to Bolívar from Haiti offering to raise volunteers in Ireland for his army. Bolívar accepted and in January 1819 entrusted him with raising an Irish legion, promising $175 for every soldier recruited, and commissioning him major-general (14 December 1819). Devereux, styling himself ‘the South American Lafayette’, arrived in Ireland about June 1819 and his venture, combining the liberation of subject nations with the romance of the Wild Geese and the conquistadors, soon captured the public imagination. In particular, the prospect of regular pay and lavish land grants in the freed colonies appealed to a large pool of unemployed soldiers, idle since the Napoleonic wars. The scheme's credibility was boosted when it was endorsed by Daniel O'Connell (qv) who organised and attended a public dinner in Devereux's honour at Morrison's hotel, Dublin, in July 1819. O'Connell was impressed by the tall, handsome Devereux, and confessed that ‘there is an unsophisticated flow of heart about him which caught my affections’ (O'Connell corr., ii, 263). A grateful Devereux granted commissions to O'Connell's nephew and to his 14-year-old son, Morgan (qv), whom he attached to his staff.
Devereux also opened offices in Liverpool and London selling commissions, and by the end of 1819 he had recruited 1,700 men. An Irish legion about 1,000 strong landed at the island of Santa Margarita, off Venezuela, in August and September 1819. The island was unsuitable as a mobilisation centre, and no preparations had been made for their arrival. The climate, disease, poor food and accommodation, and the lack of medical provision soon took their toll, and many of the Irishmen became seriously ill and died. Those who survived acquitted themselves well in action, but by March 1820 they had not received their pay and about 300 mutinied and were shipped to Jamaica. Some officers were so appalled at the conditions on Margarita that they returned to Ireland immediately, and on arrival in Dublin in December 1819 they denounced Devereux's incompetence and venality. Pamphlets were published in Dublin in 1820 attacking and defending Devereux, and the Dublin press criticised him strongly. A committee, headed by Lord Cloncurry (qv) and including Leonard MacNally (qv) and W. H. Curran (qv), met in Dublin on 29 January 1820 to examine charges against him; O'Connell spoke at length in Devereux's defence, and the committee reached no definite conclusions. Despite frequent charges that the expedition's organisation was a shambles and that Devereux's interest was purely financial, O'Connell continued to act as his lawyer and stand by him, even though this harmed his own reputation.
Devereux sailed from Liverpool on 27 April 1820 and on reaching Barbados was directed to Rio Hacha, and from there to Jamaica in search of the Irish legion. Refused permission to land at Jamaica, he eventually arrived at Margarita on 12 June 1820. He quarrelled frequently with his fellow officers and, after a dispute with the vice-president, Gen. Antonio Narino, was imprisoned for several months until acquitted by a congressional inquiry in November 1821. He met Bolívar, who absolved him from any blame for the legion's mutiny, reimbursed him generously for his expenses, and attached him to the general staff at Bogotà. In December 1823 he was appointed Colombian envoy to the courts of northern Europe, and arrived in England in 1824. In 1825, while travelling in Italy for health reasons, he was arrested and imprisoned for several weeks in Venice by the Austrian authorities, who feared he had come to stir up trouble. On his release he informed his captors that he would return to Italy with ‘sword in hand to expel the foreign tyrants from this noble country’ (Mulhall, 215).
Many of the details of his life are uncertain. Vain and unreliable, Devereux delighted in intrigue, and continually embellished his personal history, forging and altering documents to magnify his part in the liberation of South America. He suffered from blindness in his later years, possibly because of an illness contracted at Margarita, and died 25 February 1860 in Hertford St., Mayfair, London. Though he was engaged to be married in 1819, there is no evidence that he ever married.