How many UK noble families (marchionesses, earls, dukes, etc.) is Diana descended from?
And I also have the book "Ancestry of the Royal Child" by Iain Moncreiffe. How much of what is written in the book is still proven uncertain?
Diana descends from many, many UK noble families. For example:
FATHER: John Spencer, 8th Earl Spencer
GRANDFATHERS: John Spencer, 7th Earl Spencer & Maurice Roche, 4th Baron Fermoy
GREAT-GRANDFATHERS: Charles Spencer, 6th Earl Spencer; James Hamilton, 3rd Duke of Abercorn; James Roche, 3rd Baron Fermoy
GREAT-GREAT-GRANDFATHERS: Frederick Spencer, 4th Earl Spencer; Edward Baring, 1st Baron Revelstoke; James Hamilton, 2nd Duke of Abercorn; George Bingham, 4th Earl of Lucan; Edmund Roche, 1st Baron Fermoy
The link to Diana's 12-generation ancestors is broken so I'm re-posting the URL here. Just copy & paste it in your web browser. Be sure to remove the space between http:// and genealogics.
http:// genealogics.org/ahnentafel.php?personID=I00000174&tree=LEO&parentset=0&generations=12
Once you're on the site, click on a person's name for more information about them, or to trace their ancestors back more generations.
I also recommend the following book:
Richard K. Evans, The Ancestry of Diana, Princess of Wales (New England Historic Genealogical Society, 2007).