Lady Diana's 10-Great Grandfather. HM Juan Carlos' 12-Great Uncle. Philippe of Belgium's 12-Great Uncle. Grand Duke Henri's 12-Great Uncle. HM Margrethe II's 12-Great Uncle. HM Beatrix's 11-Great Uncle. HM Constantine II's 10-Great Grandfather. HM Carl XVI Gustaf's 10-Great Grandfather. HM Harald V's 11-Great Uncle.