Charles William Vane, 3rd Marquess of Londonderry KG, GCB, GCH, PC (18 May 1778 – 6 March 1854), was a British soldier, politician and nobleman. Charles Stewart (as he was before 1822) was educated at Eton and was commissioned into the British army in 1794. He saw active service in Flanders and Ireland before being elected as a member to the Irish House of Commons. In 1803 he was aide-de-camp to King George III and four years later became Under-Secretary of State for War and the Colonies. He fought in the Peninsula War under both Sir John More and Sir Arthur Wellesley (who became the Duke of Wellington).