Ashton was clerk of the closet to Mary of Modena, the wife of James II, and, after the revolution of 1688, showed himself ardently devoted to the interests of his exiled master and mistress. He appears to have held a commission of captain or major in the army, and to have been an intimate friend of Dr. Thomas Cartwright, who was bishop of Chester from 1686 to 1689, and a zealous supporter of the Stuart dynasty. By religion Ashton was a Protestant, and late in 1690 he attended a meeting of Protestant Jacobites, at which it was resolved to invite Louis XIV of France to forcibly restore James II.