| Dermont O'Brien (Lord Inchiquin V) | (____ - 1624) |
| Mary O'Brien | (____ - ____) |
| Murrough O'Brien (Lord Inchiquin 4) | (____ - 1597) |
| Murrough O'Brien (Lord Inchiquin 3) | (____ - 1573) |
| Serge Obelensky (Prince) | (1890 - ____) |
| Angus Ogilvy (Hon.) | (1928 - ____) |
| James Robert Bruce Ogilvy | (Feb 29, 1964 - ____) |
| Marina Victoria Alexandra Ogilvy | (Jul 31, 1966 - ____) |
| Sarah Ogston | (____ - ____) |
| Oldenburg | (____ - ____) |
| Oldenburg | (____ - ____) |
| Alexander_I Oldenburg (King of Greece) | (Aug 1, 1893 - Oct 25, 1920) |
| Alexia Oldenburg | (1965 - ____) |
| Christopher Oldenburg | (1888 - 1940) |
| Constantine_I Oldenburg (King of Greece) | (Aug 2, 1868 - Jan 11, 1923) |
| Constantine_II Oldenburg (King of Greece) | (Jun 2, 1940 - ____) |
| Eugenia Oldenburg | (1910 - ____) |
| George Oldenburg | (1869 - 1957) |
| George_II Oldenburg (King of Greece) | (Jul 19, 1890 - Apr 1, 1947) |
| Irene of_Greece Oldenburg (Crown Princess) | (1942 - ____) |
UP (Louisa Hanover -- Catherine Romanov) | |
BACK (Anne Mowbray -- Dermod O'Brien) | NEXT (Michael Oldenburg -- Marie Pavlovna) |