Marie Auguste Yvonne de Blacas d'Aulps 2 Jan 1851 Paris - 21 Oct 1881 Alt Aussee (1851–1881) Parents Louis, Duke of Blacas Marie de Perusse des Cars Children Stanislaus zu Sayn-Wittgenstein-Sayn Gustav Alexander Prinz zu Sayn-Wittgenstein Siblings Comtesse Louise de Blacas d'Aulps Pierre de Blacas d'Aulps Partners Alexander Graf von Hachenburg