a quality or title of honour given to princes. The kings of England and Spain had formerly no other title but that of Highness; the former till the time of James I. and the latter till that of Charles V. The petty princes of Italy first began to be complimented with the title of Highness in the year 1630; and the Duke of Orleans assumed the title of Royal Highness in the year 1631, to distinguish himself from the other princes of France.