Hamilton, James Hamilton, 3d marquess and 1st duke of
James Hamilton Hamilton, 3d marquess and 1st duke of, 1606–49, Scottish nobleman; grandson of John Hamilton, 1st marquess of Hamilton. He succeeded (1625) his father as marquess of Hamilton and earl of Cambridge and was appointed (1628) privy councilor in Scotland. He raised (1630) an army to fight under Gustavus Adolphus of Sweden in the Thirty Years War, but his expedition ended in disaster (1633). As Charles I's commissioner in Scotland, he tried to conciliate the Covenanters in 1638 and, failing, led a force against them in the first Bishops' War. Later his attempt to come to terms with Archibald Campbell, 8th earl of Argyll, apparently gave rise (1641) to the obscure plot known as the Incident, devised by James Graham, 5th earl of Montrose, to seize and probably murder Hamilton, his brother William (later 2d duke of Hamilton), and Argyll. Hamilton escaped and managed to retain the confidence of the king, being created duke in 1643. In 1644, however, he was imprisoned by Charles on suspicion of treachery, and he was freed only by parliamentary troops in 1646. In 1648, Hamilton secured ratification in the Scottish Parliament of the agreement known as the Engagement between Charles and the Scots and led the Scottish army that invaded England. Defeated at Preston, he was captured, tried by the same court that condemned Charles, and executed.