Earl Of Arran, the title of the holders of the Scotch peerage of Arran, created for Sir Thomas Boyd in 1467, but in 1503 passing by royal decree from his son, who had displeased the king, to the house of Hamilton, the successive heads of which bore this as their chief title till the higher rank of marquis and afterward of duke of Hamilton was conferred upon them. - James Hamilton, second earl of his name, died Jan. 22, 1575. He was appointed regent of Scotland upon the death of James V. in 1542, and guardian of Mary Stuart, to whom he endeavored to marry his son. Finding this impossible on account of the intrigues of Henry VIII. of England and the earl of Lennox, who also wished by this marriage to obtain the Scottish crown for their own children, Arran finally consented to her union with the dauphin of France, afterward Francis II. For his aid in promoting this alliance, the French king made him duke of Chatelherault, in Poitou, and this French title is still borne by the dukes of Hamilton. - James, son of the preceding, conceived a violent passion for Mary Stuart, and when his father failed to obtain for him her hand, he became insane from disappointment, and from the knowledge of her personal indifference to him.

While in this state he was prevailed upon to enter into a plot against her throne; but becoming conscious during a lucid interval of the iniquity of the plan, he confessed his share in it. On account of his evident insanity he was only kept in a mild imprisonment; but he took no further part in political affairs. - The titles and estates of Arran passed to his brother John, who was created marquis of Hamilton in 1599. (See Hamiltox.) - There is also an Irish earldom of Arran, conferred on Sir Arthur Gore in 1758 (earl of the Arran Islands); but none of its incumbents have become prominent in history.