William Drummond, 4th Viscount Strathallan
William Drummond, 4th Viscount Strathallan (1690 – 16 April 1746) was a Scottish Jacobite army officer and fourth son of Sir John Drummond of Machany and Margaret, daughter of Sir William Stewart of Innernytie.
Drummond was born in 1690, a year in which his father was outlawed for adhering to the House of Stuart. On 26 May 1711 Drummond succeeded as fourth Viscount of Strathallan on the death of his cousin, William. In 1712, Strathallan married Margaret Murray (died 28 May 1773), daughter of William Murray, 2nd Lord Nairne and his wife, Margaret Nairne.
Strathallan was amongst the first to join the Jacobite rising of 1715, attending John Erskine, 22nd Earl of Mar's hunting party. Serving under Brigadier William Mackintosh of Borlum, he led a battalion from Perthshire in the campaign. He was taken prisoner at Sheriffmuir and was moved to Stirling and under the terms of the Act of Grace of 1717, was neither injured nor prosecuted. Strathallan joined the army of Charles Edward Stuart on 3 September 1745, commanding the Perthshire Horse, with two troops under him led by Lieutenant-Colonel Lawrence Oliphant of Gask and Major John Haldane, he is also named as being a member of the Prince's Privy council. At the Battle of Prestonpans, he commanded the only cavalry unit in the Jacobite force, around thirty-six troopers and their servants. Strathallan was promoted to major-general and was appointed general officer commanding in Scotland, stationed in Perth, while his cavalry under the command of William Boyd, 4th Earl of Kilmarnock, joined Prince Charles in his march south. Strathallan remained in command in Scotland until superseded by Lord John Drummond.
At the Battle of Falkirk, the Perthshire Horse were at the back of the field, taking little part in the action. Several weeks later, at the Battle of Culloden, when the government ranks closed round the Jacobites and advanced on their undeployed second and third lines, Strathallan 'resolved to die in the field rather than by the hand of the executioner', his horse was killed beneath him, and according to tradition, he was run through by Colonel George Howard of the 3rd Foot. Whilst awaiting death on the battlefield, it is said he received a last sacrament of oatmeal or oatcake and whisky or water, from John Maitland of Careston, the chaplain to the Forfarshire Regiment.
Lady Strathallan, being from a Jacobite family, was held prisoner in Edinburgh Castle from 11 February—22 November 1746 while proceedings for treason were under consideration. Strathallan's younger brother Andrew Drummond, founder of the Drummonds Bank in Charing Cross was to see his business interrupted during the period of the last of the Jacobite rebellions.
There were seven sons and three daughters from the marriage of William Drummond and Margaret Murray (dau. of Lord Nairne). The eldest, James (1715-1766) became de jure 5th Viscount. The third son was Robert Drummond who became a director in his uncle's bank, Drummonds Bank and following the purchase of his Hampshire estate became known as Robert Drummond of Cadland. 
- Pittock, Murray G.H, 'Drummond, William (1690–1746)', Oxford Dictionary of National Biography, Oxford University Press, September 2004. Online database article number 8087 (May 2006).
- from notes provided from the Drummonds of Cadland family archive in 2006; courtesy of Mr Maldwin Drummond, JP, Hon DSc, DL
- H Bolitho and D Peel, The Drummonds of Charing Cross (London: George, Allen & Unwin, 1967)