Mechtild von Bentinck German countess (1877-1940) (1877–1940) Parents Wilhelm Aldenburg-Bentinck, 6th Graf Bentinck Baroness Maria Cornelia van Heeckeren van Wassenaer Children Marie Gräfin zu Castell-Rüdenhausen Siegfried Castell-Rüdenhausen Rupert zu Castell-Rüdenhausen Elisabeth Gräfin zu Castell-Rüdenhausen Siblings Frederick George Unico Williams Bentinck Countess Isabella von Bentinck William Frederick Charles Henry Bentinck, 7th Graf Bentinck Partners Casimir, 2nd Prince of Castell-Rüdenhausen
