Poss. Lady Diana's 16-Great Aunt. HM Juan Carlos' 16-Great Aunt. Philippe of Belgium's 16-Great Aunt. Grand Duke Henri's 16-Great Aunt. HM Margrethe II's 16-Great Aunt. HM Beatrix's 15-Great Grandmother. Wm. von Bismarck's 14-Great Grandmother. `Red Baron' Richthofen's 14-Great Grandmother.