La Touche, David III (1729–1817), banker, was born 29 August 1729, second surviving son among seven sons of David La Touche II (qv), banker, and Mary Anne La Touche (née Canaseele), of Dublin. David La Touche III may have been the ‘La Touche’ who entered TCD as a pensioner on 8 July 1745. He worked at the family bank from an early age and went on the Grand Tour to Italy in the years 1753–4. As a Freemason, he was deputy grand master of the grand lodge of the Freemasons of Ireland in 1767. He effectively ran the family business by the 1770s, and when his father died in 1785 he inherited all the Dublin properties (except the residence above the bank in Castle St.), a yearly income of at least £12,000, and a third share of the bank. In 1787 the bank changed its name for the last time to David La Touche & Co.
La Touche used his considerable capital and landed influence to purchase control of borough seats in the Irish parliament: he was MP for Dundalk (1761–8), Longford borough (1768–83), Belturbet, Co. Cavan (1783–90), and Newcastle, Co. Dublin (1790–1800). By effectively buying the votes in closed boroughs La Touche was able to sit in parliament for forty years until the act of union. He was made a privy councillor in 1783. His presence in the commons enabled him to lobby successfully for merchants and private bankers in Dublin and to oppose bills that would be detrimental to his own interests. A large proportion of the MPs, including such prominent figures as Henry Grattan (qv) and John Foster (qv), were heavily in debt to the La Touche bank, which made an emergency cash loan of £20,000 to the government in 1778 (but refused to make a second such loan). La Touche was one of the MPs who drew up the bill to establish a national bank. The Bank of Ireland was formally established by an Irish statute in 1782 and La Touche was unanimously elected as its first governor in 1783. His two brothers John (qv) and Peter La Touche (qv) served alongside him in the first year of the bank as directors. David La Touche and other members of his family each contributed £10,000 to the original stock of the bank. He visited the Bank of England in 1784 in order to learn how they carried out their transactions and convinced the government after a short trial period that the new bank should become a permanent fixture. He resigned as governor in 1791 and served as a director on the board of the bank 1794–7. La Touche's appointment had the potential to create serious conflicts of private and public interests, but overall he seems to have been an honest and conscientious governor. Indeed, he was respected by MPs, such as Grattan, whose religious and political views differed markedly from his after c.1780.
La Touche was by nature conservative and on the whole an ally of Dublin Castle in the period c.1780–1800. He supported, and probably inspired, a clause in the original regulations of the Bank of Ireland that prevented catholics and dissenters from becoming members of the board of directors. In parliament he fiercely opposed any attempt to remove the remaining ‘popery acts’ from the statute book. In February 1792 he was one of the MPs who rejected outright the Catholic Committee's petition for a relief bill; after a heated debate, the rejection was endorsed by a large majority of MPs. His brand of ‘patriotism’ seemed to be based primarily on a fear of catholic insurrection and French invasion, rather than a desire for legislative independence. He was an officer c.1778 in the light dragoons of the Dublin corps of Volunteers, and encouraged at least three of his sons to join various militia units in Co. Carlow and Co. Dublin. In 1798 he headed the list of subscriptions to the government (an advance of £2,000 a year and a further £2,000 a year as long as required) to help defeat the rebellion. La Touche was the only member of his family who supported the act of union, even though he stood to lose his ‘pocket’ borough seat as a result.
La Touche was a prominent figure in Dublin society and a patron of a host of charitable, municipal, and artistic organisations; a founder and first treasurer of the Irish Musical Fund in 1787, treasurer of the Grand Canal Company, vice-president of the Dublin Society 1810–17, a wide streets commissioner and a governor of the Lying-In Hospital. Musical evenings and amateur dramatics were held at his town house on St Stephen's Green, Dublin, and at his seat ‘Marlay’, named after his wife, in south Co. Dublin (which he purchased in 1764 and rebuilt in the 1780s and 1790s).
He married (18 February 1762) Elizabeth, daughter of the Rt Rev George Marlay, bishop of Dromore; they had six sons and five daughters. Their eldest son, David Marlay La Touche (1768–1816), was MP for the borough of Newcastle (1790–97, 1798–1800) and MP for Co. Carlow (1802–16) in the UK parliament; John David La Touche (b. 1772) made a number of visits to Italy in the years 1788–95 and commissioned Antonio Canova to make the ‘La Touche amorino’ (now in the NGI) in 1788. Peter La Touche (b. 1777) inherited the estate at Bellevue owned by his uncle Peter La Touche; his eldest daughter, Elizabeth (b. c.1764), was celebrated for her amateur dramatics.
David La Touche III died on 17 October 1817. A number of likenesses exist of him, including an oil portrait painted by Anton Raphael Mengs in 1753 while he was in Rome and a full-length oil c.1802 by Hugh Douglas Hamilton (qv), both in the Bank of Ireland collection. Another oil portrait c.1804 and a pastel c.1765 by Hamilton are in the NGI.