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James Johnston

1721 – 1795

British Army officer

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About James Johnston

Lived 1721 – 1795 (aged 74). James Johnston was a British military officer.

James Johnston (21 May 1721 – 26 November 1795) was a general of the British Army, colonel of the Royal Horse Guards (the Blues) then colonel of the Scots Greys where he succeeded his sister's husband, George Preston.

Early life

Johnston was the only surviving son of James Johnston (1655–1737) and his wife, Lucy (née Claxton) Johnston. His father's first wife was Catharine Poulett (a daughter of John Poulett, 2nd Baron Poulett). His sister, Lucy Johnston, was the wife of George Preston.

His father was the fourth and second surviving son of Archibald Johnston, Lord Warriston, and his second wife Helen Hay (a daughter of Alexander Hay, Lord Fosterseat). His maternal grandfather was Thomas Claxton of Dublin. Among his maternal family were aunts Frances, Countess of Rosse (and, later, Viscountess Jocelyn), Mary (née Claxton) Carter.

Career Johnston was first commissioned into the Royal Horse Guards and was present with the regiment at the Battle of Dettingen in 1743 and the Battle of Fontenoy in 1745. He became a major in the regiment on 29 November 1750, was promoted to lieutenant-colonel of the Royal Horse Guards on 17 December 1754 and commanded the regiment in Germany in several engagements during the Seven Years' War.

Desperately wounded at the battle of Minden in 1759 he was promoted to full colonel of Horse, Royal Horse Guards 9 March 1762, (the same day as his 'Irish' cousin was gazetted colonel of Dragoons) and appointed an aide-de-camp to King George III.

Promoted to major-general on 30 April 1770 on 2 May 1775 he received the additional appointment of colonel of the 11th Regiment of Dragoons in place of the marquess of Lothian and was further promoted to lieutenant-general on 29 August 1777. On 2 April 1778 he was removed from his colonelcy of Royal Horse Guards and a fortnight later appointed colonel of the 6th Regiment of Dragoons. In succession to George Preston, his sister's husband, he was made colonel of the Scots Greys on 4 February 1785, a post he held until his death.

Personal life Johnston married twice. His first marriage was on 2 March 1747 to Lady Charlotte Montagu, youngest daughter of George Montagu, 1st Earl of Halifax and the former Mary Lumley. Charlotte's sister, Frances, was the wife of Sir Roger Burgoyne, 6th Baronet. Before her death during childbirth on 28 April 1762, Charlotte and James were the parents of least three sons and three daughters, including:

Richard Johnstone Charlotte Frances Johnston (–1820), who married her cousin, Maj.-Gen. John Burgoyne, a son of Sir Roger Burgoyne, 6th Baronet and cousin to John Burgoyne, in 1772. After his death, she married Maj.-Gen. Eyre Power Trench, a son of Richard Trench, MP, and brother to William Trench, 1st Earl of Clancarty, in 1797.

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Important facts

Birth century
Occupation
Also known as
General James Johnstone, General unknown Johnstone

People in James Johnston's life

Named in this biography and alive at the same time

Contemporaries

People whose lives overlapped James Johnston's

Frequently asked questions

Who was James Johnston?

British Army officer

When was James Johnston born?

James Johnston was born on 21 May 1721.

When did James Johnston die?

James Johnston died on 26 November 1795.

What was James Johnston's occupation?

James Johnston was a military officer.

What nationality was James Johnston?

James Johnston was British.

Sources & further reading

· Wikipedia: James Johnston

· Wikidata: Q6136915

· DBpedia: James Johnston (British Army officer, born 1721)

Cite this page

APA: Biography.guide. (2026). James Johnston. https://biography.guide/james-johnston-military-officer-1721-q2fe42a38/

MLA: "James Johnston." Biography.guide, https://biography.guide/james-johnston-military-officer-1721-q2fe42a38/.

Chicago: "James Johnston." Biography.guide. https://biography.guide/james-johnston-military-officer-1721-q2fe42a38/.

Data last updated: 2026-09-20 · Spot an error? Report a correction.

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