King Charles and Princess Diana’s marital relationship has always remained a topic of intrigue on the internet. Adding to the curiosity, a letter written by Diana to her childhood friend is all set to hit the auction block, in which she shared insights into her newlywed life with Prince Charles.

Gorringe’s auction house announced the sale of Princess Diana’s valuable items that belonged to her childhood friend, Katherine Hanbury, who studied with her at West Heath Girls’ School from 1973 to 1977. According to The Guardian, the treasure trove includes “The Honeymoon Letter,” written by Diana on a royal-crested paper, which will be presented for auction on July 7.

Following their grand “wedding of the century” at St. Paul’s Cathedral in London, England, on July 29, 1981, Charles and Diana began their three-month honeymoon with a 12-day cruise on the Royal Yacht Britannia.

In a three-page letter written from Balmoral Castle in Scotland, dated September 27, she admitted to having a “blissful honeymoon” with plenty of sunshine and “calm seas”, further expressing excitement about spending time with Charles in Scotland through the end of October.

“I adore being outside all day & hate London!” she further added. Reflecting on her marriage to King Charles, she said, “It’s wonderful being married – I think it’s safe to say that after two months…!”

The Princess married Charles while she was just 20 and also spoke about adjusting to her new life within the royal family, describing it as “a case of playing with grown-ups!”

Apart from the letter, the collection also comprises school photos of the Princess at her school. In one of the pictures, she could be seen sitting with her friends, including actress Tilda Swinton and film director Joanna Hogg. Another click is from a low-key Thanksgiving service conducted at St. Martin-in-the-Fields in November after her demise that August.

The entire collection is expected to sell for an estimated value of roughly $5,400 to $8,000. It is set to go up for auction on July 7 at Gorringe’s Fine Art & Interiors sale, just weeks before what would have marked the 45th wedding anniversary of Charles and Diana.

King Charles and Diana welcomed sons Prince William and Prince Harry in 1982 and 1984, respectively, before separating in 1992 and eventually getting divorced in 1996. Unfortunately, the following year, Diana died in a tragic car accident in Paris amid reported infidelity allegations on both sides.

Meanwhile, books and manuscripts specialist at Gorringe’s, Albert Radford, stated that the collection would offer a rare glimpse into Diana’s life before she stepped into the royal responsibilities and public life.

He stated that, according to his client’s (Katherine) memories from their time at West Heath Girls’ School, Diana was remembered as humble and grounded, with a strong focus on family life and an appreciation for simple, everyday joys.

He added that Katherine remembers Diana as somebody who would volunteer to clean the headmistress’s house, and it is the memories like these that would spotlight and present the real young Diana, who was different from the public persona created by others.