Handwritten letters and cards from Diana, Princess of Wales, have revealed the sweet relationship between Prince William and Harry when they were growing up.

The letters, addressed to Diana’s parents’ housekeeper Violet Collison (affectionately known as Collie by the princess), are to be sold at auction.

Violet was head housekeeper to John Spencer and Frances Roche at Park House on the Sandringham Estate in Norfolk where Diana spent her childhood years, even witnessing her birth.

Sweet handwritten thank-you notes and a decade of correspondence are being auctioned off next week, and share some moving insights into the relationship between a young William and Harry.

In one letter, estimated to be worth £1,200 and written from Kensington Palace on September 25, 1984, Diana thanked Collie for a gift of some bibs for baby Harry.

Handwritten letters and cards from Diana, Princess of Wales , have revealed the sweet relationship between Prince William and Harry when they were growing up. Harry and William are pictured at home in 1986

She noted that ‘William adores his little brother & spends the entire time pouring an endless supply of hugs & kisses over Harry’.

She joked that the display was ‘wonderful to watch, if we’re allowed near!’ demonstrating the inseparable bond between the two young royals.

The depiction of a tactile and loving relationship between William and his baby brother is a far cry from their famously frosty connection these days.

In his book, Spare, Harry went as far to call William his ‘archnemesis’ and said the pair have always ‘competed’ and detailed physical altercations between the pair.

It is believed the trigger that caused the rift to develop between William and Harry was when the then Duke of Cambridge advised his younger sibling to ‘take things slow’ when he first began dating Meghan Markle in 2017.

Relations became so sour that they reportedly didn’t talk for weeks after Harry’s wedding, where William was best man.

Harry and Meghan’s decision to step down as senior royals in 2020 – informally known as Megxit – and the way it was handled, left William and Charles devastated.

In the documentary – Harry & Meghan: An African Journey – the Duke of Sussex admitted he and William are ‘certainly on different paths at the moment’.

In a letter written to her parents’ housekeeper Violet Collison and dated from September 25, 1984, Diana writes: ‘William adores his little brother and spends the entire time pouring an endless supply of hugs & kisses over Harry’

It’s a far cry from the relationship between the two princes these days, which has famously become frosty (pictured in 2021)

Violet Collison, affectionately known as ‘Collie’, worked for John Spencer and Frances Roche at Park House on the Sandringham Estate and witnessed the future Princess of Wales ‘ birth. Diana pictured when she was young

Diana said the sweet display was ‘wonderful to watch, if we’re allowed near!’ Pictured: Notes being sold at auction

Another letter was dated just three weeks before the wedding between Diana and Charles in 1981

He told ITV’s Tom Bradby: ‘Inevitably stuff happens. But we’re brothers, we’ll always be brothers.’

A source previously told People that the brothers’ relationship is ‘forever changed’ and they ‘won’t get back to the way they were’. Harry is looking straight ahead at his future with his family,’ they added.

Diana’s correspondence, which is being auctioned by Sworders in Stansted Mountfitchet in Essex, reveals that Collie remained in Diana’s thoughts throughout her life.

Most of the letters to Collie are thank-you notes for birthday and Christmas presents given to Diana and her children, William and Harry.

These notes often include a line or two about Diana’s life at the time.

One double-sided letter in the collection – penned on Buckingham Palace headed notepaper and dated just three weeks before Charles and Diana’s wedding – is expected to fetch £1,200.

‘Everyone frantically busy here doing last minute decorations on the house and things like that,’ it reads.

‘Family all far too excited and, at the moment, the bride to be has remained quite calm!’

The 24 lots cover from 1979 through Diana’s wedding to Prince Charles and birth of her two sons in the 1980s, to the order of service for her funeral in 1997

After retirement she lived in a bungalow near Sandringham, where Diana would often visit her secretly without her security detail

Now, Collie’s family are selling the collection of cards, letters, photos and invitations at Sworders Auctioneers of Essex

Most of the letters to Collie are thank-you notes for birthday and Christmas presents given to Diana and her children

Another sweet letter sees the late Princess thanking Collie for gifts sent to her young sons.

It said: ‘William found the parcels and dived into the paper before I could stop him.’ That letter is on Kensington Palace paper with a ‘CD’ logo for Charles and Diana – and also has an estimate of £1,200.

After the marriage of Diana’s parents ended, Collie followed Diana’s mother to London in 1967, working for her and her new husband until her retirement in 1973.

Collie died in 2013 at the age of 89.

Luke Macdonald, head of art and estates at Sworders, said: ‘Violet Collison, Collie, was Diana’s parents’ housekeeper when they lived at Park House. She knew Diana from when she was born and remained a constant in her life.

‘At all points she would try to return to see Collie. When she stayed at Sandringham she would escape to see Collie without her security.’

He expressed that they offer a ‘lovely chapter in the history of Diana’.

‘She was one of her closest confidantes,’ Luke continued. ‘They give a nice insight – before the wedding she describes everyone being frantically busy but the bride-to-be staying calm and there are letters about William and Harry that are really sweet.

The ‘once unbreakable’ bond between Prince William and Prince Harry has suffered a ‘devastating breakdown’

Relations became so sour that they reportedly didn’t talk for weeks after Harry’s wedding, where William was best man

‘Collie died in 2013 and the family has decided now is the time to sell them as they are just living in a box and not being enjoyed, there are too many family members to divide them up.

‘They have spoken to Diana’s sisters to make sure they were okay with them selling.

‘What is special about these is they tell a story, they are not just somebody’s collection. From the first Christmas card to the last, they are a complete story of her friendship and relationship with Diana.

‘Everyone wants a little part of Diana, she connected with people and was very much the people’s princess.’

This was made worse after he and Meghan were interviewed by Oprah Winfrey.

The collection of more than a dozen letters and cards is to be sold as part of the Out of the Ordinary Sale on July 30. The items are expected to sell for thousands of pounds.