Letters written by Princess Diana have provided a glimpse into the relationship between Prince William and his brother Prince Harry. These previously unseen correspondences between Diana and Violet Collison, the head housekeeper to her parents at Park House on the Sandringham Estate in Norfolk, are set to be auctioned. One of these letters recounts a poignant moment shared between her two children.

She wrote: "William adores his little brother and spends the entire time pouring an endless supply of hugs and kisses over Harry." Collison, affectionately called Collie by Diana, remained close with the family until her passing in 2013 at the age of 89. The letters span from before Diana's marriage to Charles to the early years of Prince William and Harry's lives.

Now, these correspondences are up for auction by Sworders in Stansted Mountfitchet, Essex. Most of the letters to Collie are thank-you notes for birthday and Christmas gifts given to Diana and her children, William and Harry. One of the latest letters includes greetings for Christmas and New Year from 1994, accompanied by a photograph of Diana, William, and Harry smiling.

Another letter, written on Buckingham Palace notepaper and dated July 8, 1981, three weeks before the Royal Wedding, is double-sided. In it, Diana wrote "everyone frantically busy here doing last minute decorations..

. the bride to be has remained quite calm!". This particular letter, which is in its original envelope addressed in Diana’s hand - is exp.