Appointed Colonel of the 29th Regiment of Foot on the 5th December 1792.
Born on the 17th September 1755. He accompanied his father to St. Petersburg in 1768. After his return home he studied the law of Scotland, and in 1776 was admitted a Member of the Faculty of Advocates.
On his father’s death, his lordship took up the army as a profession, and in June 1777 was gazetted to a Cornetcy (commission or rank of a cornet which was the lowest rank of a commissioned cavalry officer) in the 7th Queen’s Dragoons; proceeded as extra
A.D.C. to Sir Henry Clinton to the seat of war in America, and in October was present at the storming of Forts Clinton and Montgomery.
In November was appointed to a Lieut.-Colonelcy, and on 10 December was promoted to a Troop in the 17th Light Dragoons present at the engagement of Monmouth Court House.
In 1778 raised the British Legion, of which he was given command and provincial rank of Colonel.
On the 13th April 1779 was appointed Major of the 38th regiment of Foot, with which he served in the affairs of Springfield and Elizabeth Town Point.
On the 2nd February 1781 was appointed Captain and Lieut.-Colonel in the Coldstream Guards, and on the 6th October 1789 exchanged to the Lieut.-Colonelcy of the 29th Regiment of Foot; became Brevet Colonel on the18th November 1790, and on the 5th December 1792 was appointed Colonel of the Regiment.
Lord Cathcart
On the 3rd October 1794 was promoted to Major-General; served in Flanders, and the following year in Holland and North Germany, when he commanded the whole of the Light Cavalry.
Returned to England in 1796; in 1797 commanded a brigade of Cavalry at Weymouth, and was on the 7th August 1797 transferred to the Colonelcy of the 2nd Life Guards.
Promoted to Lieut.-General on the 1st January 1801 ; in the autumn of 1805 was ordered to Russia as Ambassador.
His Lordship was next appointed commander-in-chief of the Forces in Scotland, and in May 1807 to command the Military Forces in the Expedition to Copenhagen.
In 1814 was created Earl Cathcart, and died at Cartside, Glasgow on the 16th June 1843.