He was an admiral in the Royal Navy, a Member of Parliament and Lord-Lieutenant of Kirkcudbrightshire and Wigtownshire.

On his death, the titles passed to his younger brother, the eleventh Earl.

As of 2020[update] the present holder of the titles is the thirteenth earl's second cousin once removed.

John Stewart, third son of the third Earl, was a brigadier-general in the army and also sat as Member of Parliament for Wigtownshire.

Keith Stewart, third son of the sixth Earl, was an Admiral and Member of Parliament.

Montgomery Granville John Stewart, sixth son of the seventh Earl, represented Kirkcudbrightshire in the House of Commons.

James Henry Keith Stewart, eighth son of the seventh Earl, was Member of Parliament for Wigtown Burghs.

Keith Stewart (1814–1859), younger son of the eighth Earl, was an admiral in the Royal Navy.

The Earls of Galloway are now considered to be the senior branch of Clan Stewart,[2] although their exact descent is debated.

[3] The family seat is Cumloden House, near Newton Stewart, Dumfries and Galloway.

He was educated at Eton College and in 2003 was living at 9 Lennox Garden Mews, Knightsbridge, London SW1.