John Stuart, Lord Mount Stuart

Colonel John Stuart, Lord Mount Stuart, was born on 25 September 1767 at Grosvenor Square in London. He was the son of John Stuart, 1st Marquess of Bute, and the grandson of John Stuart, 3rd Earl of Bute, who served as Prime Minister of Great Britain. His mother was the Honorable Charlotte Jane Windsor, daughter and heiress of Herbert Windsor, 2nd Viscount Windsor.

He received education at Eton College and subsequently attended St John's College, Cambridge. In 1790, he was elected as the Member of Parliament for Cardiff, a seat he held until his death in 1794. In 1791, he succeeded his father as colonel of the Glamorgan Militia. From 1793 until his death, he also served as Lord-Lieutenant of Glamorganshire.

On 12 October 1792, Lord Mount Stuart married Lady Elizabeth McDouall-Crichton, daughter of Patrick McDouall-Crichton, 6th Earl of Dumfries, and Margaret Crauford. They had two sons: John Crichton-Stuart, 2nd Marquess of Bute (born 10 August 1793, died 18 March 1848), and Lord Patrick James Herbert Crichton-Stuart (born 25 August 1794, died 7 September 1859). Both sons adopted the surname "Crichton-Stuart" in 1805.

In 1817, he obtained the rank associated with that of a son of a Marquess, a status he would have held had he outlived his father. Lord Mount Stuart died on 22 January 1794 at Bassingbourn Hall near Stansted, Essex, aged 26, following injuries sustained in a fall from his horse a month earlier. His wife, Lady Elizabeth, survived him by three years, passing away in July 1797 at the age of 24.