Duchess Sophia Charlotte of Oldenburg Prussian princess (1879-1964) (1879–1964) Parents Princess Elisabeth Anna of Prussia Frederick Augustus II, Grand Duke of Oldenburg Children Siblings Alexandrine von Holstein-Gottorp Nikolaus, Hereditary Grand Duke of Oldenburg Duchess Altburg of Oldenburg Duke Friedrich August of Oldenburg Ingeborg Alix von Oldenburg Duchess Margarete of Oldenburg Partners Harald von Hedemann Prince Eitel Friedrich of Prussia