Anton-Günther, Duke of Oldenburg Head of the Grand Ducal Family of Oldenburg (1923-2014) (1923–2014) Parents Princess Helene of Waldeck and Pyrmont Duke Nikolaus, Hereditary Grand Duke of Oldenburg Children Christian Duke of Oldenburg Helene von Holstein-Gottorp, Herzogin von Oldenburg Siblings Duke Friedrich August of Oldenburg Duchess Eilika of Oldenburg Duke Peter of Oldenburg Duchess Altburg of Oldenburg Duke Egilmar of Oldenburg Huno Herzog von Oldenburg Duchess Rixa of Oldenburg Duke Johann of Oldenburg Partners Ameli, Duchess of Oldenburg