Prince Charles' pet nickname for Camilla Parker Bowles has been revealed by a letter the Prince wrote to his other half on the day of their Civil Wedding - April 9, 2005.
In "One Is Deeply Concerned: The Prince Charles Letters, 1969-2011" assembled by David Stubbs, reveals a collection of correspondence from Prince Charles.
The book, published in 2011, includes a special letter Prince Charles wrote to Camilla on the day of their Civil Wedding - where he refers to his now wife as 'sugar lump'.
Charles begins the letter with: "You know what I'd really like to say to you, but given our exchanges have in the past fallen into the wrong hands with decidedly embarrassing consequences.
He continued: "But you, my dear: you are different. Hang it all, raisins to my nuts, with you I feel I can talk about biodegradable Wellingtons for hours without the other party rolling their eyes."
Later, Prince Charles and Camilla Parker Bowles married at the Windsor Guildhall in an intimate civil ceremony.
A source close to the royals, Ingrid Seward, editor of Majesty magazine, said Camilla is the best thing that has ever happened to Charles.