Example image of eyePlorer eyePlorer map for 'Grand Ducal Highness': Abbreviation Grand duke Charlotte, Grand Duchess of Luxembourg Prince Felix of Bourbon-Parma Royal Highness Baden Grand Duchy of Hesse Luxembourg Imperial Highness Tuscany Austria Archduke Highness Serene Highness Line of succession to the throne of Baden Order of Prince Henry Charles Frederick, Grand Duke of Baden GDH Grand duchy Style (manner of address) Royal Marriages Act 1772 Princess Victoria of Hesse and by Rhine