WELLESLEY, HENRY, Baron Cowley (1773–1847), diplomatist, born on 20 Jan. 1773, was the youngest son of Garrett Wellesley or Wesley, first earl of Mornington [q. v.], and Anne, daughter of Arthur Hill, first viscount Dungannon. He was brother of Richard Colley Wellesley, marquis Wellesley [q. v.], of Arthur Wellesley, duke of Wellington [q. v.], and of William Wellesley-Pole, baron Maryborough (afterwards third Earl of Mornington) [q. v.] In his early years he served in the army, exchanging from the 40th foot into the 1st foot guards in April 1791. His diplomatic career began with his appointment as secretary to the Stockholm legation in January 1792. Three years later he was elected to the Irish parliament for the family borough of Trim. In July 1797 he accompanied Lord Malmesbury to Lille as his secretary. Two months later he sailed for India with his brother, then Lord Mornington, afterwards the Marquis Wellesley. Besides the valuable assistance he gave to the viceroy as private secretary, Henry Wellesley while in India rendered some important special services. Together with his brother, Sir Arthur Wellesley (afterwards Duke of Wellington), he acted as one of the commissioners for the settlement of Mysore after the defeat of Tipú Saib, and was afterwards despatched to England to give a detailed account of the war and the treaties which concluded it. Lord Wellesley described him as ‘next to himself most completely informed on these topics.’ Henry Wellesley left India on 15 Aug. 1799, and had returned thither by March 1801. Soon afterwards he was sent to Lucknow to demand from the vizier of Oude a cession of territory sufficient to defray the cost of the increased subsidised force which the viceroy had sent thither. It was also required that the vizier should in his administration act in conformity with the East India Company's instructions. A treaty was concluded, and Wellesley was appointed lieutenant-governor of the ceded territory. The court of directors of the company, though acknowledging his services, resented the appointment, as Wellesley was not a member of the service, and ordered that he be removed forthwith. But they were overruled by the board of control, who pointed out that the Oude mission was an extraordinary service, and that Wellesley had declined all emoluments except his salary as private secretary to the viceroy. He resigned the lieutenant-governorship in March 1802, and immediately returned to Europe. In the following November the directors wrote to the viceroy a full acknowledgment of his brother's services in Oude. Lord Wellesley requested Castlereagh to communicate all his despatches to Henry Wellesley, adding: ‘Every part of my conduct and the whole course of my sentiments on all subjects are familiar to Mr. Henry Wellesley, in whom I repose the most implicit confidence’ (Wellesley to Castlereagh, 31 Dec. 1803, quoted by Pearce). In the subsequent articles of accusation against the Marquis Wellesley, his brother's name was joined with his own, and, in connection with the Oude affair, Henry Wellesley was (baselessly) charged with offering ‘alarming threats and personal insults’ to the vizier, and with imposing heavy taxes after the cession (Parl. Debates, vii. 391; Pearce, ii. 178–81).
After his arrival in England, Wellesley entered upon a short period of political life. He was returned to the English parliament as member for Eye on 20 April 1807, and two years later was also chosen for Athlone, but elected to sit for Eye. During 1808–9 he acted as one of the secretaries to the treasury, and on 20 Dec. 1809 was sworn of the privy council.
In May 1809 he had resumed his diplomatic career, resigning his seat in parliament. He accompanied the Marquis Wellesley to Spain as secretary to the embassy. When, a few months later, the marquis returned to England, Henry Wellesley took his place as envoy-extraordinary. On 1 Oct. 1811 he was named ambassador. During the Peninsular war he gave valuable support to Wellington. In 1812 he was knighted, and in January 1815 created G.C.B. He claimed to have prevented Wellington's deprival of the command of the Spanish army by the ultra-liberal regency; and in 1814 prevailed upon the king of Spain to sign a treaty relinquishing for ever the scheme of a Bourbon alliance. After the peace he concluded a treaty with Spain containing an article by which Anglo-Spanish commercial relations were replaced upon the footing they had been in 1796. In 1817 he negotiated with the same country a treaty for the abolition of the slave trade.
Wellesley left Spain in March 1822, and on 3 Feb. 1823 was named ambassador at Vienna. He remained in Austria for eight years. In August 1827 he told Wellington that he thought he had more than once prevented a rupture between England and Austria. But he complained that Canning never recognised his services. Wellesley's policy towards Austria was probably too conciliatory to please that minister (Sir H. Wellesley to Wellington, December 1827).
In this year, according to Colchester
