Taaffe, Denis (1759–1813), clergyman, polemicist, and historian, was born in Termonfeckin, Co. Louth, and baptised 3 February 1759 in the local parish of Clogher, the fourth of six children of Laurence Taaffe, a farmer, and his wife, Mary (née Gallagher). After being educated at local schools, including the classical school of a Mr Carolan, he decided to become a Franciscan and from 1775 studied at Franciscan colleges in Bouley (France) and Prague, taking his vows at the latter. He read widely in literature and history as well as theology, and learned Hebrew in Prague from a rabbi, with whom he was friendly. He also befriended Charles Lennox (qv), later fourth duke of Richmond and lord lieutenant of Ireland (1807–13), and acted as his guide and interpreter during his visit to Prague. Taaffe returned to Ireland in 1786, stopping off in London where he became involved in a drinking session with a fellow Irishman, and awoke next morning in the Bridewell to find himself robbed of all his valuables. He was assigned to a convent in Drogheda, but fell out with his ecclesiastical superiors because of his excessive drinking, and became a Church of Ireland clergyman on 8 November 1788. His heavy drinking and recalcitrance soon put him in trouble with his protestant superiors too, and after a short while he returned to the catholic faith, but was not allowed exercise his priestly functions. An accomplished linguist, Taaffe had a good knowledge of Irish, Greek, Latin, Hebrew, French, Italian, German and Dutch, and supported himself (with difficulty) in Dublin by translation work and teaching languages. According to John O'Donovan (qv), he taught Irish to William Haliday (qv) and George Petrie (qv). The contrast between his poverty and erudition, added to his dissolute lifestyle and general eccentricity, made him a well-known Dublin character.
During the 1790s he became sympathetic to the radical views of the United Irishmen, although there is no evidence that he took the United Irish oath. He was strongly critical of the sectarian policies of the protestant ascendancy, and their encouragement of Orange violence. He supported the 1798 rebellion, and claimed to have fought with the Wexford rebels at several engagements including the battle of Ballyellis (29 June 1798), suffering a wound that rendered his left hand useless. However, he criticised the United Irishmen for their excessive reliance on French aid, maintaining that if the French had managed to conquer Ireland they would readily have traded it for a West Indian sugar island. A strong opponent of the act of union, he denounced the prospect of Ireland losing its legislative independence in The probability, causes and consequences of a union between Great Britain and Ireland (1798). The loyalist John Claudius Beresford (qv) singled out Taaffe's pamphlet as a ‘pretty specimen’ of publications written ‘to agitate the people’ against the union (Castlereagh correspondence, ii, 51). Taaffe followed this with The second part of Taaffe's reflections on the union (1799). In February-March 1799 Taaffe edited the Dublin periodical The Shamroc, which was similar in style, content, and rhetorical strategy – radical republican message expressed with irony – to the defunct Belfast United Irish paper, the Northern Star. In it Taaffe denied the need for a legislative union and claimed that only a ‘reformed legislature, by dispensing equal justice and impartial laws, could cement the people by the ties of a common interest and a common country’ (Shamroc, 15 Feb. 1799). Arrested for seditious libel on 14 March 1799, he wrote to Edward Cooke (qv), the undersecretary at Dublin Castle, declaring that the main purpose of his paper was ‘to decry the folly and wickedness of religious bigotry’, but he also made clear his reprobation of the ‘impolicy and injustice’ of the protestant ascendancy's political monopoly (30 Mar. 1799, NAI 620/8/75/4).
He was released soon afterwards, took lodgings in James's St, Dublin, and continued to earn a precarious living from occasional writing and translating. After the union his interests shifted from political to historical and cultural topics, and he launched a scathing attack on England's ‘civilising mission’ in Ireland, publishing a Vindication of the Irish nation and particularly its catholic inhabitants from the calumnies of libellers (1801). He further developed this theme in Succinct views of catholic affairs in reply to McKenna's thoughts (1805), challenging the charges of barbarism and heresy advanced by English writers against the ancient Irish. He also published A defence of the catholic church, against the assaults of certain busy sectaries (1808). A native Irish speaker, in December 1806 Taaffe became a founder and secretary of the Gaelic Society, which aimed to investigate and revive ancient Irish literature, publish Irish historical and literary documents, and develop the literary and ecclesiastical history of Ireland. On behalf of the Gaelic Society he wrote an unpublished ‘Introduction to the Irish language’.
Taaffe was helped financially by two leading catholics, John Keogh (qv) and Florence McCarthy (1761–1810), coadjutor-bishop of Cork (1803–10), to write a history of Ireland. An impartial history of Ireland, from the period of the English invasion to the present time, appeared in four volumes (1809–11); the narrative ends in 1795, owing to Taaffe's death. A short unfinished fifth volume (essentially a rambling commentary on British government in Ireland) was published posthumously in 1819. Although not particularly original or well researched (it relied heavily on Francis Plowden's (qv) Historical review of the state of Ireland (1803)), Taaffe's Impartial history was, for the most part, written clearly and coherently; sympathetic to the catholic and native Irish position, it argued that Irish catholic loyalty to the British crown had been poorly rewarded. Clearly showing the extent to which the political struggle of the period was fought on historiographical ground, Taaffe repeatedly took issue with David Hume's History of England (1754–62), maintaining that British writers on Irish affairs had generally ‘brandished the pen of defamation with a mind no less hostile than that of the warrior yielding the sword in battle’ (Impartial history, i, p. iv). Convinced that history could be magistra vitae, Taaffe declared his will to complete a work from which ‘governors may learn the impolicy and weakness of the former system of ruling Ireland . . . and the people may learn to mitigate the asperity of religious prejudice’ (ibid., i, p. iii). The idea that partisan histories had nourished prejudice and helped to divide Irish catholics and protestants was one of Taaffe's abiding convictions.
Taaffe seems to have curbed his drinking and loose living towards the end of his life: an obituary noted that ‘he became very penitent . . . and died like a good Christian’ (Irish Magazine (Aug. 1813), 384). He died 30 July 1813 in Dublin, and was buried in an unmarked grave in the churchyard of St James's church.