MONMOUTH, JAMES, Duke of, a natural son of Charles II. and Lucy Walters, was born at Rotterdam in 1619, and was educated in France. His winning manners rendered him popular, but his foolish vanity made him the dupe of designing tacticians, who induced him to head an insurrection against his uncle James II. in June 1685. He was beheaded on the 15th July of the same year. (See BRITAIN.)