Billy Tallon's collection of royal paraphernalia, which goes on sale Saturday, is an engaging insight into the life of the British monarchy.
Tallon joined the Royal Household when he was just 15 and, over the 51 years that followed, he became a trusted and valued senior servant.
When he died last year, he left a vast, carefully-preserved collection of cards, letters, photographs and presents the Royal Family had given him over the years.
It is, says CBS News correspondent Richard Roth, "a grand assortment of art and antiques and objects hard to classify, things he was given and things he bought -- royal memorabilia, on a remarkable scale."
Tallon friend and lawyer Stephen Lansley told Roth, "I don't think he set out to start a collection. I think he just liked nice things ... and he just bought one thing and then another thing and, over the years, he formed a collection."
Tallon, Roth observes, "didn't throw stuff out." In addition to the honeymoon note from Diana, he saved one from her written after Prince William was born that said, "We're not sure what's hit us, except a very strong pair of lungs.'"
"This is a lovely collection of quite amazing bits and pieces," said Janet Canon at Reeman Dansie, the auction house that is running the sale. "Lots of people are flying in from overseas, especially from America and Canada, to take part in the auction."
Tallon's long-term partner, Reginald Wilcox, also worked as an under-butler in the Royal Household, and Tallon inherited his memorabilia when he died. Saturday's auction includes some of Wilcox's possessions. The items are being put up for sale by members of Tallon's family.
Tallon, known affectionately as "Backstairs Billy" (his official job title in the royal household was "'steward and page of the backstairs," according to Roth), devoted his whole life to the Royal Family.
He was especially attached to the Queen Mother, for whom he was chief steward. " He was," Roth says, "a butler -- who once said his duty was to keep the Queen Mother smiling."
His estate includes a handwritten note the Duke of Kent sent him after the Queen Mother died, saying: "I know all too well how grievous must be her loss to you and what an enormous gap she will leave in your life."
Roth remarked that, "In the world of upstairs, downstairs, it's said, William Tallon managed to meet royalty somewhere in the middle: a servant who cultivated friendships among artists and developed an eye for talent, a footman rewarded for long and faithful service."
Head auctioneer James Grinter showed Roth Tallon's Royal Victoria medal in gold. "Very few people are awarded it in gold," Grinter pointed out. And Tallong got "the silver version with a bar, which means it was awarded twice."
Canon said the 700 lots are valued at an estimated $500,000, but that the collection is likely to sell for a lot more. "There are people who really, really love the Royal Family and would pay anything to get some of these pieces. There are also some genuinely valuable pieces of art in the collection."
Canon said Buckingham Palace had inspected all the items and approved the auction. A Buckingham Palace spokesman, speaking on condition of anonymity in line with Palace policy, would not comment on the sale.