General William Steuart (1643 – 4 June 1726), was a Scottish soldier and Commander-in-Chief of Queen Anne's Forces in Ireland. He was a benefactor of Hanover Square, London, donating the land and laying the first stone of St George's, Hanover Square.
William Steuart (also sometimes spelt Stewart) was the second son of Colonel William Stewart (d.1691), adjutant to the Marquess of Montrose at the Battle of Philiphaugh, by his wife Barbara, the grand-daughter of Captain James Stewart, Earl of Arran and Chancellor of Scotland. His paternal grandfather, William Stewart of Burray, Orkney and Mains, Wigtownshire, was the elder brother of the 1st Earl of Galloway. Steuart was a nephew of Lt.-Col. Sir Archibald Stewart (d.1689), the first Baronet of Burray, and his father's sister, Jean, married Sir James Sinclair of Murchil, making Steuart a first cousin of John Sinclair (d.1705), 8th Earl of Caithness.
His father had been granted lands in Ireland by Charles II of England in lieu of arrears of pay due to him as a Cavalier officer during the English Civil War, and it was there that William Steuart grew up. He joined the army and became a Captain with the 1st Foot Guards before his promotion by William III of Orange to Lieutenant-Colonel of the 16th Foot. He was subsequently promoted to Colonel of the 9th Regiment. Before 1681 he was promoted to Brigadier-General and served with distinction during the Irish Campaign, 1689-1691. At the first Siege of Limerick (1690) he was badly wounded in the right hand, permanently disabling him, but he went on to assist in the relief of Derry, and was wounded again at Limerick and Athlone.
He was promoted to Major-General in 1696. On Christmas Eve, 1700, he fought a duel with Colonel Bellew. Within two yards of his opponent, Steuart, with his left hand, shot Bellew through the hat. In return Bellew threw away his pistol saying that he did not desire to kill Steuart. By 1703 he was promoted to Lieutenant-General. In 1711, in the absence of the Duke of Ormonde, Queen Anne appointed him Commander-in-Chief of her forces in Ireland. The same year he was made a full General and Privy Councillor. George I later removed him from his colonelcy of the 9th Foot, suspecting him of 'favouring the Chevalier'. He lived at Hanover Square, London and was a member of Parliament for Waterford. He owned considerable amounts of land in Ireland.
General Steuart died 4 June 1726, and is buried with his first wife in the vault of the Duke of Buckingham at Westminster Abbey. In his will he left £5,000 to endow a school for the poor boys of his parish, St. George's, in London. He also donated the land on which St George's, Hanover Square was built, laying the first stone in 1721.
He was married twice. His first wife, The Rt. Hon. and Lady Katherine FitzGerald, Viscountess Grandison, was the widow of Brigadier-General Hon. Edward Villiers (d.1693), the eldest son of George Villiers, 4th Viscount Grandison. She was the daughter and heiress of Sir John Fitzgerald of Dromana House (Villierstown), Co. Waterford, by his wife Katherine, second daughter of John Power (1599–1661), 5th Baron La Poer, and her guardians included Charles II of England. She died in December, 1725. One month later Steuart married Eliza, daughter of Sir Rowland Alston (1654–1697), 2nd Bart., of Odell Castle, Bedfordshire, by his wife Temperance, daughter and heiress of Thomas Crew, 2nd Baron Crew. Neither wife bore him children.
After various charitable donations the bulk of the remainder of his will was divided between his brother and sister and the children of his elder brother, Captain James Steuart (d.1689), to whom he had acted as guardian. His nephews were: Colonel John Steuart (d.1762) of Dublin, who inherited the General's land at Leighlinbridge, Co. Carlow, where his son, William, built Steuart/Stewart's Lodge in 1752; Major Charles Stewart, who had a 'very considerable fortune of his own' bought Bailieborough Castle in 1724; and James Steuart, Admiral of the Fleet, who was the executor of the General's will. Their fourth and eldest brother, Brigadier-General The Hon. William Steuart (d.1736) of Ballylane, Co. Waterford, whose monument stands in Bath Abbey, was cut off with only a shilling. This was most likely due to his marrying the General's stepdaughter, Hon. Mary FitzGerald-Villiers, compromising some of the General's properties.