Stewart [afterwards Vane], Charles William (1778–1854), 3rd marquess of Londonderry , soldier and diplomat, was born 18 May 1778 at Mary Street, Dublin, the only son of Robert Stewart (qv), landowner and MP for Co. Down (1771–83), and later 1st marquess of Londonderry, and his second wife, Frances Stewart (née Pratt), the daughter of Charles Pratt, 1st Earl Camden. Charles was the half-brother of Robert Stewart (qv), Lord Castlereagh, and this connection was to be the single most important factor in driving his career as a soldier, politician, and diplomat.
Educated at Eton (1790–94), Stewart narrowly avoided drowning in an unsuccessful attempt to save the life of his friend Lord Waldegrave in 1791. He decided upon a military career, purchased a commission as an ensign in MacNamara's regiment of foot on 11 October 1794, and advanced to lieutenant and captain before the year was out. He served on the continent in the war against France, stationed in the Netherlands and Austria, and was wounded at the battle of Donauworth; as a result of his injuries in that and later engagements his sight and hearing were impaired, disabilities that were to be a major liability in his later career.
When his uncle, the 2nd Earl Camden (qv), was appointed lord lieutenant of Ireland in 1795, Stewart was named as aide-de-camp, before being commissioned a major and then lieutenant colonel in the Royal Irish dragoons. He served during the 1798 rebellion and, after the disbandment of his regiment in 1799, became lieutenant colonel of the 18th light dragoons. A brief campaign in the Netherlands followed. By this time his half-brother was chief secretary for Ireland and engaged in the passing of the act of union. Charles was persuaded to enter the Irish house of commons to vote for the measure and, in the final few months of the parliament, represented two constituencies. He was first MP for Thomastown, Co. Kilkenny, taking his seat on 18 March 1800 but vacating it after just fifty-one days so that he could contest the prestigious open seat of Co. Londonderry. He was unchallenged and was sworn in on 29 May; he continued to represent this constituency in the new united parliament (1801–14). On 25 September 1803 he was made aide-de-camp to the king and in 1805 published Suggestions for the improvement of the military force of the British empire in defence of Pitt's additional force bill.
At Westminster, Stewart was determined to support Castlereagh in all matters; as a result he was viewed largely with indifference. Opposing the short-lived ministry of Lord Grenville (qv), he clashed with Henry Grattan (qv) on 2 June 1806, making the modest claim that he was no Irish orator, just an Irish soldier. He was under-secretary to Castlereagh at the war office (1807–9), but spent much of his time from August 1808 fighting in the Peninsular campaign. As a cavalry commander Stewart was considered dashing and brave, but also foolish and irresponsible. Thanks to Castlereagh's influence, he served as adjutant general to Sir Arthur Wellesley (qv) from April 1809 but, although he received the thanks of parliament on a number of occasions, he was thought too reckless for serious responsibilities.
Disgruntled at the stalling of his military career, Stewart decided to become a diplomat, but the same failings followed him. He was successively envoy extraordinary and minister plenipotentiary to Prussia (April 1813–14), ambassador to Vienna (August 1814–23) and a plenipotentiary at the Congress of Vienna (1815). The titles were more impressive than his duties: his chief responsibility at Vienna was taking verbatim notes. His natural exuberance caused some embarrassment to the other British diplomats: he was a notorious womaniser and his liaisons with aristocrats and prostitutes alike attracted much unwanted attention. He cut quite a figure at Vienna: his bright yellow leather boots earned him the names ‘Lord Pumpernickel’ and ‘the Golden Pheasant’, and for his brawling he was dubbed ‘Fighting Charlie’. He was raised to the peerage as Baron Stewart of Stewart's Court and Ballylawn, Co. Donegal, on 1 July 1814 and received numerous honours from Prussia, Portugal, Russia, and Sweden, as well as honorary doctorates from the universities of Oxford and Cambridge.
Stewart married, on 8 August 1804, Lady Catherine Bligh, daughter of the 3rd earl of Darnley, with whom he had one son. Catherine died on 11 February 1812 and he then married, on 3 April 1819, Frances Anne-Emily Vane-Tempest (1800–65), daughter of Lady Antrim and heir to vast estates in Durham and Co. Antrim; they had three sons and four daughters. Proud of this connection he took the surname Vane in place of Stewart in 1829.
After Castlereagh's suicide Stewart succeeded as 3rd marquess of Londonderry on 12 August 1822. For the rest of his life he was determined to defend his brother's reputation and so continued the feud with George Canning. No longer trusted with political responsibilities, he withdrew from regular involvement in politics and tended his new estates at Durham and Co. Down. He was created Earl Vane and Viscount Seaham in the peerage of the United Kingdom on 28 March 1823, but Londonderry remained the superior title. He became heavily involved in the coal trade of the north-east of England and was a hated figure for his treatment of striking workers. Reflecting on his glorious years as a soldier, he published two accounts, Narrative of the peninsular war from 1808 to 1813 (1828) and Narrative of the war in Germany and France in 1813 and 1814 (1830). In 1830 he fought a duel with the younger Henry Grattan (qv) over the ‘bedchamber’ crisis. This was his second duel and his response on both occasions was the same: he waited until his opponent had fired and then discharged his pistol in the air. For his opposition to the reform bill in 1831 he was almost attacked by a mob but escaped unscathed.
Disappointment marred his final years. On 10 January 1837 he became a full general, but Queen Victoria opposed his receiving any political appointments. He himself wanted to be ambassador to Paris, or lord lieutenant of Ireland, and rejected the offer of returning as ambassador to Vienna in 1841. He died 6 March 1854 of influenza, at his home at Long Newton, near Wynyard Park, Co. Durham. A statue was erected in his honour at the market place at Durham by Disraeli on 2 December 1861. Upon his death his son from his first marriage, Frederick William Robert Stewart (1805–72), succeeded as 4th marquess of Londonderry. His eldest son from his second marriage, George Henry Robert Charles William Vane-Tempest (1821–84), succeeded as Earl Vane and later succeeded his half-brother as 5th marquess of Londonderry.
Regarded as vain and indiscreet by his contemporaries, Stewart is best remembered by historians as the editor of the twelve volumes of the Castlereagh correspondence, published between 1848 and 1853. Although his advancement owed much to family connections, Stewart had many redeeming features which compensated for his failings. He was brave (the veteran of twenty-five battles in Ireland, the Netherlands, and Portugal), loyal, and conscientious. Although family reputation, and in particular that of his half-brother, meant everything to him, he none the less opposed his own son in 1852 when he stood for election in Co. Down because of his genuine belief that there was a better candidate.