A Fabergé cigarette case given to King Edward VII by an ancestor ... snake biting its own tail that Edward VII received from his mistress Alice Keppel in 1908, with the unbroken serpent a symbol ...
Judith Keppel is descended from Alice Keppel, the mistress of Edward VII and the great-grandmother of the Prince of Wales's companion, Camilla Parker Bowles. The link makes the two women cousins.