Here is one of three descents tracing Elizabeth Willoughby from Henry fitz Henry, bastard son of King Henry I of England:
This line is no longer valid. See generation #12 below for the break in the line:
1. Elizabeth Willoughby 1512-1562 = Sir Fulke Grevill, knight
2. Edward Willoughby 1491-1517 = Margaret Nevill
3. Sir Robert Willoughby, Lord Broke 1470-1521 = Elizabeth Beauchamp
4. Sir Robert Willoughby, Lord Broke 1452-1502 = Blanche Champernoun
5. Sir John Willoughby ca. 1421-1477 = Anne Cheyney
6. Sir John Willoughby ca. 1400-1346/7 = Jane Welby
7. Sir Thomas Willoughby d. 1417 = Elizabeth Neville
8. Robert Willoughby, Lord of Eresby = Margery la Zouche d. 1391
9. William la Zouche, Lord Zouche = Elizaberh de Ros d. 1380
10. William de Ros, Lord Ros = Margery de Badlesmere 1306-1363
11. Bartholomew de Badlesmere = Margaret de Clare ca. 1286-1333
12. Thomas de Clare = Julian fitz Maurice
The line breaks here. Julian fitz Maurice was the daughter of Maurice' FIRST wife, Maud de Prendergast. Ela Longespee, Maurice' second wife, died without issue.
13. Maurice fitz Maurice fitz Gerald = Emmeline de Longespee ca. 1250-1291
14. Stephen de Longespee = Emmeline de Ridelisford d. 1276
15. Walter de Ridelisford d. ca. 1244 = Annora
16. Walter de Ridelisford = Amabilis fitz Henry
17. Henry fitz Henry ca. 1105-1157 = unknown
18. Henry Beauclerc, King of England 1068-1135 = mistress, Nest verch Rhys, Princess of Wales