Constanza, would you consider providing us with Murray's bibliography of original source material? I'll send you the complete bibliography via e-mail. I've tried to sort out the original sources from the rest, but frankly, I don't know where to draw the line.

it would be helpful to discover what is available that I don't already know about yet. :-) Not much, I guess ;-)

I can probably help you with this, as I have researched those families pretty extensively and have many books and a database of them (and many others). Do you have any particular questions I could try to answer?

Thank you Laura. I think I've figured it out at last, but I'd like to check it with you. The problem seems to be that, unless I am wrong, there are at least three Georgianas Cavendish.

There's a Georgiana, Lady Spencer, "matriarch of the Cavendish at the end of the eighteenth century" and mother of Georgiana Cavendish (later 5th Duchess of Devonshire, who is also a Cavendish, so I guess they were cousins?) and Harriet Cavendish (later Lady Bessborough). The Duchess of Devonshire is the mother of Lady Georgiana Cavendish (later Viscountess Morpess), Lord Hartfield and Lady Harriet Cavendish (Hary-O, later Lady Granville). Lady Bessborough is the Mother of Caroline and Frederick Ponsonby and the lover of Lord Granville (incidentally, by the time Granville married Hary-O, were they still having an affair? Do you know when were they married?). Caroline Ponsonby is married to William Lamb and his brother George is married to Hary-O's half sister Caroline St. Jules (daughter of the 5th Duke of D. and Lady Elizabeth Foster - do you happen to know where she came by that surname?). I don't know where to place Harry Cavendish (which is a cousin of the 5th Duke, but I don't know what relation he has with the remaining Cavendishes) and Frederick Lamb. Also, there's a reference to Caroline Lamb's following in the steps of her mother, aunt and uncle; but I don't know who the uncle was and what he did.