New letters by Princess Diana reveal Prince Harry's naughty streak and her sons' strong bond

A series of letters penned by Princess Diana are going up for auction. In the correspondences with Buckingham Palace steward Cyril Dickman, the late royal speaks of the bond between her young sons – and the rebellious side of eight-year-old Prince Harry. Cheffins auction house will have the letters for sale on Jan. 5, where the estimated value is £15,000. Offering insight into William and Harry's childhood, they will no doubt prove a big hit with royal fans.

In one note, dated Sept. 20, 1984, when Prince Harry was just five days old, Diana wrote: "Dear Cyril, it was so kind of you to have sent us such a lovely card, on the arrival of our small son – we were both greatly touched by your thoughtfulness and enormously appreciated it.

TAP TO VIEW GALLERYA photograph of Princess Diana with Prince Harry and Prince William as children wearing school uniformsLetters written by Princess Diana reveal the close bond between sons, Prince William and Prince Harry

"William adores his little brother and spends the entire time swamping Harry with an endless supply of hugs and kisses, hardly letting the parents near!"

Diana, then 23, continued: "The reaction to one tiny person's birth has totally overwhelmed us and I can hardly breathe for the mass of flowers that are arriving here! This is just to say a big thank you, Cyril. For thinking of us at this particularly happy time, with lots of love from Diana."

In another letter, dated Oct. 17, 1992, Diana shares an update on her two sons. "The boys are both well and enjoying boarding school a lot," the royal remarked. "Although Harry is constantly in trouble!"

A photograph of Princess Diana with Prince Harry and Prince William as children wearing school uniformsThe royal also revealed that Harry was "constantly in trouble" at boarding school

Cyril was the head steward at Buckingham Palace for more than 50 years, having begun his career watching out for fires of the roof of the palace during the Blitz. He was the advisor to Sir Anthony Hopkins for his role as a butler in The Remains of the Day, and was made a Freeman of the City of London following his retirement at the age of 65.

Cyril passed away in 2012 at the age of 85, and the letters were recently uncovered by his grandson who has put them up for auction.

"He was much loved by the royal family. When he was ill, towards the end of his life, Prince Charles came to see him at his home in London," Matthew Dickman told the Cambridge News. "We have decided to sell some of the items he had purely because there's too much of it to keep."

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