Prince Christian-Sigismund of Prussia Prussian prince (b. 1946) Parents Grand Duchess Kira Kirillovna of Russia Louis Ferdinand, Prince of Prussia Children Princess Isabelle-Alexandra of Prussia Princess Irina of Prussia Prince Christian of Prussia Siblings Princess Kira of Prussia Princess Xenia of Prussia Princess Marie Cécile of Prussia Prince Friedrich Wilhelm of Prussia Prince Michael of Prussia Prince Louis Ferdinand of Prussia Partners Christiane Grandmontagne Nina Gräfin von Reventlow