Soldier and politician. Born in Petersham (Surrey), he succeeded his father, Archibald Campbell (1682 - 1761), the 1st Duke. Along with James Douglas (1662 - 1711), the 2nd Duke of Queensberry and John Erskine (1675 - 1732), the 6th Earl of Mar, Campbell was a leading supporter of the 'Act of Union' (1707). Campbell was also a successful soldier, taking a leading role in the army. He fought with the English Army in the War of the Spanish Succession (1701 - 14), with the Duke of Marlborough against the French at Oudenarde (1708) and Malplaquet (1709). Promoted to the rank of Field-Marshal, he led the government army at Sheriffmuir (1715) and defeated the Jacobites led by the same Earl of Mar (the so-called 'Bobbing John') who had earlier worked for the Union. He had been created the Earl of Greenwich in 1705 to ensure his support for the Union, and he was granted the same Dukedom for his continued loyalty (1719). He was appointed Commander-in-Chief of the army in the year before his death.