One of his great-grandfathers was Henry Colley of Castle Carbery, King's County, Ireland. That family from Rutland, England settled in Ireland ' Henry VIII, where they were distinguished soldiers and administrators. Henry's sister Elizabeth married Garret Wesley I of Dangan, Meath, younger son of Valerian Wesley and Ann Cusack. Henry's youngest son by Mary Usher, only daughter of Sir William Usher of Dublin, was Richard Colley who in 1728, on the death without issue of his first cousinGarret Wesley II inherited the Wesley estates with the proviso in the will that he and his heirs should adopt the name and arms of Wesley. He made the necessary formal declaration in 1728 and became known as Richard Wesley. In 1746 he was created 1st Baron Mornington, an ancient barony of the Wesleys. His sister Ann married William Pole of Ballyfin, Queen's County. Mornington married Elizabeth Sale, producing as heir Garret Wesley, 2nd Baron Mornington, who was created in 1760 1st Earl of Mornington in County Meath. In 1759 he married Ann Hill and produced five successful sons; of these, most prominent, are:
William, above, inherited the Pole estates from William Pole of Ballyfin, the childless brother of his aunt Ann Colley. The will of Pole required the family name honour the inheritance, here Pole, thus William Wesley became in 1778 William Wesley-Pole. Wesley-Pole, born in 1763, also had an outstanding career, having been an Irish member of parliament for Trim, a Governor of Queen's County, and after the Union of 1800 a Westminster member for that county also, and having served as Chief Secretary for Ireland. He married in 1784 Katherine-Elizabeth, eldest daughter of Hon. John Forbes, Admiral of the Fleet and they had the 4th Earl'''.
Early life
He was born William Wesley-Pole on 22 June 1788 in London and baptised at St George's, Hanover Square, on 19 July. His family, quite broadly defined, changed their surname to the more archaic 'Wellesley' in the early 1790s. His first marriage was on 14 March 1812 to Catherine Tylney-Long, known in fashionable London society as "The Wiltshire Heiress", and believed to be the richest commoner in England. Two months before the ceremony William Wellesley-Pole assumed the additional surnames of Tylney-Long, changing his name by Royal Licence. During this period William enjoyed a political career, first as a ToryMember of Parliament for the pocket borough of St Ives from 1812 until 1818, and then for Wiltshire, where his wife's family was influential. However, he was principally known for his dissipation and extravagance. On one occasion in 1814, Long-Wellesley held a grand fête in Wanstead House and its gardens to celebrate his uncle the Duke of Wellington's victory over Napoleon, attended by the Prince Regent, a number of other members of the royal family, and over a thousand dignitaries. He was also known to be a friend of the Irish poet Thomas Moore and of Lord Byron. On 8 August 1822, as his debts began to mount, he was appointed a Gentleman Usher to King George IV, an appointment which rendered him immune to arrest for debt, but he was soon to leave England entirely.
While in Europe evading his creditors, Long-Wellesley began a relationship with Helena Paterson Bligh, the wife of Captain Thomas Bligh of the Coldstream Guards, eventually abandoning Catherine, who died two years later on 12 September 1825. Catherine had implied in a letter to her sisters that her husband had given her a venereal disease. Long-Wellesley married Helena in 1828, but this marriage as quickly proved calamitous. As a notorious rake he was unable to afford to make prudent investments in his first wife's property, but nor could he sell or mortgage it, having only a life interest in it. As life tenant he arranged with other beneficiaries for the demolition and carving up of Wanstead House's estate, the proceeds of which repaid some of his great debts. He returned to Parliament in 1830, again as a member for St Ives. He was one of the Tories who broke with the first his uncle's Ministry and brought about its fall on 15 November 1830. He was returned and as a knight of the shire for Essex from 1831 to 1832. In the years following Catherine's death, he sought to regain control over his children, who were in the care of Catherine's two unmarried sisters, Dorothy and Emma. He was especially interested in William, the eldest, on whom Catherine's fortune had devolved. His uncle, the Duke, fighting one of his furious defensive actions, intervened on behalf of the children to keep the hapless William from his father. Deprived of the custody of his children by the Court of Chancery, he was committed to the Fleet prison by Lord Brougham in July 1831 for contempt of court; Long-Wellesley invoked parliamentary privilege, but his plea was rejected by the committee of privileges of the House of Commons. For some time he was in and out of court on charges of libel, and various other matters relating to his quest for custody of his children.
Decline and death
He led a very dissipated life and lived for a time in Brussels to avoid his creditors. In his last years he lived on a small pension of £10 a week allowed by his cousin Arthur Wellesley, 2nd Duke of Wellington. From 1842 he was styled Viscount Wellesley, and succeeded his father as Earl of Mornington in 1845. He died in lodgings in Thayer Street, Manchester Square, London, on 1 July 1857, from heart disease. The obituary notice three days later in the Morning Chronicle claimed that he was "A spendthrift, a profligate, and a gambler in his youth, he became debauched in his manhood... redeemed by no single virtue, adorned by no single grace, his life gone out even without a flicker of repentance". His coffin is in Catacomb B, Kensal Green Cemetery, London.
