Princess Diana's unearthed letter shows she really was about the people

The heartfelt letter included a signature from her young sons at the time, Prince William and Harry

When was the last time you sent a thank you card? Or, for that matter, got one? It's always a special gesture, whether you're giving or receiving, but getting one from an actual Royal? That's taking things to a different level.

People reported that a thank-you note from Princess Diana is hitting the auction block at William George & Co — and it shows just how polite and proper the late Princess of Wales was.

The letter goes back to 1989 and was sent to Sergeant George Plumb of Scotland Yard’s elite Close Protection Group. In the note, Diana thanked him for helping with Prince William's seventh birthday. The letter includes a heartfelt message, which is on official Kensington Palace stationery, includes Diana's signature as well as William and Harry's.

PHOTO: FILE

"Dear Sgt Plumb, It was so very kind of you and your team to have come here today on William’s birthday. I cannot begin to tell you what pleasure the display gave to all those little people and their mothers! I know how particularly busy you all are at the moment," the letter read.

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"So it meant even more to us that you and the motorbike boys were able to take part in the birthday celebrations! This comes with our warmest possible thanks. It finished, “Yours sincerely Diana, William, Harry.”

PHOTO: FILE

The auction lot includes a second letter from Ann Beckwith-Smith, Diana's lady-in-waiting, and a Buckingham Palace envelope that's addressed to 'Sgt George Plumb Special Escort Group.'

"We are delighted to bring this rare item, signed not just by Diana, Princess of Wales, but also by her children, to market," Robin Gray, managing director of William George, said. "Authentic, personal pieces such as this are much sought after and we have experienced a lot of interest in this sale already." Running through to April 23, the next minimum bid for the letter is $10,000.

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