Never-before-seen Princess Diana school photos and a honeymoon letter go to auction on 7 July

A remarkable archive of photographs and personal correspondence is offering a rare and intimate look at Princess Diana's formative years.

The collection, gathered by Katherine Hanbury — a childhood friend who attended West Heath Girls' School alongside Diana from 1973 to 1977 — has been entrusted to UK auction house Gorringe's, which will offer it for sale from 7 July.

Four candid school photographs

The archive contains four colour photographs that have never previously been made public, all taken during the future royal's time at West Heath.

Two show Diana inside her dormitory, one captures her outdoors with the school sports field visible behind her, and the fourth is a group shot of Diana and fellow pupils relaxing in the sun against one of the school's buildings. Personal letters written by Diana to Hanbury are also part of the lot.

A birthday card signed "Diana (S)"

Among the correspondence is a simple, handwritten birthday card sent by the future princess to Hanbury, signed "Diana (S)" — the "S" standing for Spencer. The addition suggests there may have been more than one Diana in their year group at the time.

'Deeply unassuming and domestically minded'

Albert Radford, Books & Manuscripts Specialist at Gorringe's, shared his assessment of the collection in a statement to PEOPLE. "This intimate archive offers a rare glimpse of Diana, Princess of Wales, before duty and fame had the final say.

"Through our client's recollections from West Heath Girls' School, Diana comes across as deeply unassuming and domestically minded; someone whose real ambition was simply to have a family and take pride in ordinary things," he said.

"She remembers Diana volunteering to clean the house of the headmistress, and it is memories like this, and the collection that has come to light, that present the real young Diana in a way that is completely at odds with the public persona that was created by others," Radford continued.

"She appears here as a young woman suspended between love and history – hopeful, unguarded, and not yet entirely claimed by the institution that would come to define her. In these small, fragile traces, innocence lingers – along with a quiet, stubborn belief in something as simple and elusive as love."

Diana's school years and early life

Diana was not a strong academic pupil, failing her O-levels on two occasions. She departed West Heath at the age of 16 in 1977 — the same year she would first encounter her future husband, then-Prince Charles, though the pair did not begin courting until 1980. They wed on 29 July 1981, and honeymooned at Balmoral Castle in Scotland.

The honeymoon letter

It was from Balmoral that Diana wrote what has been described as the "Honeymoon Letter" to Hanbury, a piece also included in the collection.

Dated 27 September 1981, the newly titled Princess of Wales wrote to her friend: "Dear Katherine, I can't tell you what a lovely surprise I got opening your card. Thank you so much for putting pen to paper and wishing me well."

The letter runs to three pages, written on embossed notepaper bearing the royal crest in red at the top of each sheet.