Guillaume VI of Serenierre

Titles and styles

 * 29 July 1961 – 17 May 1968: Her Royal Highness Princess Diana Marie-Julliette of Cascon
 * 17 May 1968 - 1 December 1976: Her Royal Highness Princess Diana of Montaigne
 * 1 December 1976 - 5 March 1981: Her Royal Highness The Princess Diana, Madame Royale
 * 5 March 1981 - present: Her Majesty The Queen of Belmont

As Queen, her full style and title are:


 * Her Majesty Diana the First, By the Grace of God Almighty, Queen Regnant of Belmont and its Realms, Grand Duchess of Couserans, Lord Protector of Tréguier, Sovereign-General of Visidame, Defender of the Faiths, Commander-in-Chief of the Armed Forces, Maître de l'Famille Montaigne, Duchess of Saint-Lô.