James Campbell was born in Lawars, Perthshire c1680. His father was the 2nd Earl of Loudoun. His mother was Lady Margaret Montgomerie, daughter of Hugh, 7th Earl of Eglinton. His brother Hugh Campbell was the last Secretary of State of Scotland prior to the Acts of Union.
He joined the army at the age of 13 and was an officer in the Scots Guards, then the Royal Scots Fusiliers, fighting in the War of the Spanish Succession which included Marlborough’s famous victories. In 1706 he was appointed CO of the Scots Greys. He was appointed Colonel of the (9th) Regiment on 27 July 1715 but transferred back to the Scots Greys as their Colonel on 15 Feb 1717. The King also appointed him Groom of the Chamber and he became the Whig MP for Ayrshire in that year. In 1738 he was appointed Governor of Edinburgh Castle.
He also fought in the later War of the Austrian Succession, notably at the battle of Dettingen for which he was knighted. At the battle of Fontenoy he was mortally wounded when a cannonball tore off his leg. He died of his wound on the same day, 11 May 1745.
In 1720 Campbell married Lady Jean Boyle Mure, daughter of the 1st Earl of Glasgow. They had two children, James and Margaret. James had his name changed to Mure-Campbell and later inherited the title 5th Earl of Loudoun.
