Unlike his father, the 8th Earl and Marquis of Argyll, the 9th Earl was consistently loyal supporter of the Royalist cause fighting as Colonel of the Scots Foot Guards both at Dunbar in 1650 and a Worcester in 1651. He joined the Earl of Glencairn's Rising with a Lieutenant-General's commission but later submitted to Cromwell. In favour at the Restoration, his efforts on behalf of his father annoyed the Scots Parliament to the extent that they succeeded in having him imprisoned under sentence of death, which sentence was delayed by Royal command. Released in 1663, his lands and title (but not the Marquisate) were restored. Refusing to sign the Test Act, he was condemned to death for treason in 1681 but escaped from Edinburgh Castle disguised as his stepdaughter's serving maid and eventually got away to Holland. In 1685 he returned at the head of an invasion of Scotland designed to restore the Protestant religion; his attempt, like that of the Duke of Monmouth's simultaneous landing in England, failed after an abortive campaign and the Earl was captured and then executed. His courage during his last, short captivity and at his death has long been remembered.