Wesley, Garrett (1735–81), amateur musician, politician, and 1st earl of Mornington , was born 19 July 1735, probably at Dangan Castle, Co. Meath, the only surviving son of Richard Wesley (originally Colley), later 1st Baron Mornington, and Elizabeth Wesley (née Sale). Educated by Mr Disney, he entered TCD on 9 October 1751, graduating BA (1754) and MA (1757). His godmother, Mrs Delany (qv), encouraged him to learn the violin; when he was 13 she wrote that he was ‘a most extraordinary boy. . . [with] more knowledge than I ever met with in one so young’ (G. E.C., Peerage, ix, 236). In 1757 he founded the Musical Academy, which successfully combined music making with charitable fund-raising. Entering the house of commons, he was briefly MP for Trim, Co. Meath (1757–8). Elected on 16 July 1757, he was sworn-in on 25 October, but had to resign his seat on 31 January 1758 when his father died and he succeeded as 2nd Baron Mornington. Nevertheless, he was nominated to serve on sixteen committees during his short spell in the commons.
In 1764, after completing his doctorate in music in TCD, he was appointed the first professor of music at the university. A respected amateur musician as a composer, violinist, and harpsichord player, he received widespread praise when he played for the king, George III. Some of his glees, such as ‘Here in cool grot’ and ‘Come fairest nymph’, were considered classics of their kind by contemporaries. On 2 October 1761 he was created Viscount Wellesley of Dangan Castle and earl of Mornington; it was rumoured that he owed this advancement in the peerage to having impressed the king with his music. He was named a privy councillor on 24 September 1776. He was grand master of the Grand Lodge of Irish Freemasons (1776–7). He died 22 May 1781 at Kensington, London, and was buried in Grosvenor chapel, South Audley St.
He married (6 February 1759) Anne, daughter of Arthur Hill-Trevor (qv), 1st Viscount Dungannon; they had nine sons and one daughter. His eldest son, Richard Colley Wesley (qv) (later Wellesley) became 1st Marquess Wellesley, William Wesley (qv) (later Wellesley-Pole) was chief secretary for Ireland, and a younger son, Arthur Wesley (qv) (later Wellesley), became 1st duke of Wellington.