Earl of Mornington

Earl of Mornington is a title in the Peerage of Ireland, since 1863 a subsidiary title of the dukedom of Wellington. It was created in 1760 for the Anglo-Irish politician and composer Garret Wellesley, 2nd Baron Mornington. He was made Viscount Wellesley, of Dangan Castle in the County of Meath, at the same time, also in the Peerage of Ireland. Lord Mornington was the eldest son of Richard Wesley. The latter represented Trim in the Irish House of Commons and was elevated to the Peerage of Ireland as Baron Mornington in 1746. Born Richard Colley, he inherited the Dangan and Mornington estates in County Meath on the death of his first cousin Garret Wesley in 1728 and assumed the same year by Royal license the surname of Wesley in lieu of his patronymic (see below for earlier history of the family). Four of the first Earl of Mornington's sons gained distinction. The third son was Arthur Wellesley, 1st Duke of Wellington, who defeated Napoleon Bonaparte at the Battle of Waterloo in 1815 (see Duke of Wellington), while the fifth was the diplomat Henry Wellesley, 1st Baron Cowley (see Earl Cowley). Lord Mornington was succeeded by his eldest son, Richard, the second Earl. He used the original family surname of Wellesley in lieu of Wesley. He was a prominent soldier, diplomat and politician. In 1797 he was created Baron Wellesley, of Wellesley in the County of Somerset, in the Peerage of Great Britain, which entitled him to a seat in the British House of Lords. In 1799 he was further honoured when he was made Marquess Wellesley, of Norragh, in the Peerage of Ireland. However, he was said to be bitterly disappointed at not receiving a dukedom or at least an English peerage of high rank. He referred to his Irish marquessate an a "double-gilt potato". Lord Wellesley had several illegitimate children by his French mistress Hyacinthe-Gabrielle Roland (they were married in 1794 after the birth of their children). One of them, Anne, married as her second husband Lord Charles Bentinck. They were great-great-grandparents of Queen Elizabeth II.

As Lord Wellesley had no legitimate children the English barony of 1797 and the marquessate became extinct on his death in 1842. He was succeeded in the other titles by his younger brother William Wellesley-Pole, 1st Baron Maryborough, who became the third Earl of Mornington. He was also a politician and notably served as Chief Secretary for Ireland between 1809 and 1812 and as Chancellor of the Irish Exchequer between 1811 and 1812. Born William Wesley, he assumed by Royal license in 1781 the additional surname of Pole on succeeding to the estates of his cousin, William Pole. In 1798 he assumed by Royal license the surname of Wellesley-Pole in lieu of Wesley-Pole. In 1821 he was raised to the Peerage of the United Kingdom as Baron Maryborough, of Maryborough in the Queen's County. He was succeeded by his son, the fourth Earl. He married Catherine, daughter and coheir of Sir James Tylney-Long, 7th Baronet (see Tylney-Long Baronets). She was known in London society as "The Wiltshire heiress" and was believed to be the richest commoner in England. On his marriage he assumed by Royal license the additional surnames of Tylney and Long. Lord Mornington is chiefly remembered for his dissipated lifestyle which brought about the destruction of the Tylney family estate of Wanstead House. He was succeeded by his eldest and only surviving son, the fifth Earl. He had been the subject of a bitter custody battle between his father and his two maternal aunts (who had wanted him to be placed under the guardianship of his great-uncle the Duke of Wellington) and later fought a legal battle with his father over the sale of contents of the family seat Draycot House. Lord Mornington died unmarried in 1863 when the barony of Maryborough became extinct. He left all his landed property to his father's cousin Henry Wellesley, 1st Earl Cowley. He was succeeded in his Irish titles by his first cousin once removed, Arthur Wellesley, 2nd Duke of Wellington. The title Earl of Mornington is now used as a courtesy title by the heir apparent to the Marquess of Douro, himself the heir apparent to the Duke of Wellington. As of 2010 the title is held by courtesy by Arthur Wellesley, Earl of Mornington, grandson of Arthur Wellesley, 8th Duke of Wellington.

The Wesley or Wellesley family descended from Sir Richard de Wellesley (15th century). His grandson Sir William Wellesley (d. 1602) lived at Dangan, County Meath. The family estates passed down the male lines. One of Wellesley's daughters, Alison, married John Cusack. Their son Sir Thomas Cusack served as Lord Chancellor of Ireland between 1551 and 1554. His daughter, Katherine, married Sir Henry Colley (or Cowley) (16th century), of Castle Carbery, County Kildare. Their grandson Sir Henry Colley represented Monaghan in the Irish Parliament. One of Sir Henry's sons, Dudley Colley (or Cowley), was a member of the Irish Parliament for Philipstown. His son Henry Colley (or Cowley) was the father of Henry Cowley, who represented Strabane in the Irish House of Commons, and of Garret Wesley, 1st Baron Mornington. The aforementioned Garret Wesley (d. 1728) was a descendant of Sir William Wellesley (d. 1602) as well as the son of Elizabeth, daughter of the aforementioned Dudley Colley, also the paternal grandfather of the first Baron Mornington.

The country seat of the Wellesley family was Dangan Castle, near Trim, County Meath. The Dublin residence of the family was Mornington House, Merrion Street.