in the Flanders Campaign of the French Revolutionary Wars, and on the Rhine and Danube in 1795. He was lieutenant-colonel of the 5th Royal Irish Dragoons by the time he helped put down the Irish Rebellion of 1798. In 1803, Stewart was appointed aide-de-camp to King George III. In 1795 his father was created Viscount Castlereagh and in 1796 Marquess of Londonderry in the Irish peerage. In 1800, Charles Stewart was elected in the Tory interest to the Irish House of Commons as member of parliament for Thomastown borough, County Kilkenny, in place of George Dunbar, and after only two months exchanged this seat for that of Londonderry County, being replaced at Thomastown by John Cradock. After the abolition of the Irish Parliament with the Act of Union in 1801, In July and August 1802 Stewart was re-elected for the country in the first general election of the United Kingdom and sat until the parliament's dissolution in 1806. He was reelected again in 1806, in 1807, after which he became Under-Secretary of State for War and the Colonies, and again in 1812. In July 1814 he was summoned to the House of Lords.and replaced as MP for Londonderry by his uncle Alexander Stewart of Ards. First marriage and son On 8 August 1804 at the church of St George's, Hanover Square, London, Charles Stewart married Lady Catherine Bligh. She was the 4th and youngest daughter of the 3rd Earl of Darnley. She was three years older than he. On 7 July 1805 the couple had a son, named Frederick, who was to become the 4th Marquess of Londonderry. She died during the night of 10–11 February 1812, of fever following a minor operation, while her husband was on his way home from Spain. Son by Catherine Bligh: Frederick William Robert Stewart, 4th Marquess of Londonderry (1805–1872) Peninsular War The remainder of his military career developed during the Napoleonic Wars, more exactly in the Peninsular War. Corunna The war started with the Corunna Campaign (1808–1809), in which the British troops were commanded by Sir John Moore. In this campaign Charles Stewart commanded a brigade of cavalry, and played, together with Lord Paget, a prominent role in the cavalry clash of Benavente where the French General Lefebvre-Desnouettes was taken prisoner. He suffered from ophthalmia during the latter stages of the retreat. Moore sent him back to London carrying dispatches for Castlereagh and