Duke Nikolaus of Oldenburg (1840-1886) (1840–1886) Parents Princess Therese of Nassau Duke Peter of Oldenburg Children Olga von Ostenburg, Countess von Ostenburg Vera von Ostenburg, Countess von Ostenburg Alexandra von Ostenburg, Countess von Ostenburg Siblings Georg Friedrich Alexander von Holstein-Gottorp, Herzog von Oldenburg Duke Constantine Petrovich of Oldenburg Marie Friederike Cäcilie of Oldenburg Duchess Alexandra of Oldenburg Duchess Therese Petrovna of Oldenburg Duke Alexander Petrovich of Oldenburg Ekaterina Petrovna of Oldenburg Partners Maria Bulatzelly
