EXCLUSIVE: Princess Diana's Poignant Honeymoon Letter to Prince Charles Revealed

Princess Diana described her honeymoon with the future King Charles III as a "tremendous success" in a touching handwritten letter, which offers a remarkable contrast to her later accounts of the couple's troubled marriage, RadarOnline.com can reveal.

The previously private correspondence, written in 1981 when Diana was 20, forms part of a collection of nine letters addressed to her family's former housekeeper, Maud Pendrey.

The documents, which were put up for auction, reveal the princess' affectionate reflections on her first weeks of marriage following her spectacular royal wedding to Charles, then 32.

Writing after returning to Balmoral from a two-week Mediterranean cruise aboard the royal yacht Britannia, Diana expressed gratitude to Pendrey for her kindness during the wedding celebrations.

She wrote: "I do hope you weren't too tired after all the wedding activities, and that you were able to see a lot from where your seats were."

The princess went on to describe the honeymoon in glowing terms, suggesting she and Charles had enjoyed a welcome opportunity to recover from the exhausting preparations surrounding their internationally televised ceremony.

"The honeymoon was a tremendous success, and we had a glorious time catching up on our lost energy and sleep," Diana noted. "I just wanted you both to know how deeply touched I am by your thoughtfulness and, again, a million thanks.

"Endless love and affection – Diana."

The correspondence provides a rare contemporary glimpse into Diana's apparent optimism at the beginning of a marriage that would eventually collapse amid allegations of infidelity and profound personal unhappiness.

Her enthusiastic description also contrasts sharply with revelations she made years later about the tensions that overshadowed the honeymoon.

In recordings made during sessions with her voice coach, subsequently featured in a documentary, Diana recalled discovering Charles had received cufflinks bearing intertwined initials from Camilla Parker-Bowles, now Queen Camilla, 79.

Diana believed the jewelry symbolized the continuing closeness between Charles and Camilla, whose relationship would become central to the breakdown of their royal marriage.

She said: "On our honeymoon, cufflinks arrive on his wrists."

Diana described the distinctive design and her immediate suspicions about who had given Charles the present.

She said: "Two Cs entwined like the Chanel 'C.' Got it. One knew exactly. So I said, 'Camilla gave you those, didn't she?' He said, 'Yes, so what's wrong? They're a present from a friend.'

"And boy, did we have a row. Jealousy, total jealousy. And it was such a good idea – the two Cs – but it wasn't that clever."

The contrasting accounts illustrate the gulf between Diana's private correspondence immediately after the wedding and her retrospective description of the marriage's difficulties.

Diana and Charles married at St. Paul's Cathedral in London on July 29, 1981, in a ceremony watched by hundreds of millions worldwide.

Their marriage ended in divorce in 1996, one year before Diana died aged 36 following a car crash in Paris.

The letter forms part of a wider collection of personal notes exchanged between Diana and Pendrey, offering further insight into the princess's relationships with people who knew her before she entered the royal family.

Diana transformed the British monarchy through her compassion, accessibility, and extraordinary global appeal.

Born Diana Spencer in 1961, she married Prince Charles in 1981 and became one of the world's most photographed women.

Mother to Princes William and Harry, she challenged royal conventions through her humanitarian work, particularly supporting people affected by HIV/AIDS, homelessness and landmines.

Her marriage collapsed amid intense media scrutiny, ending in divorce in 1996. Diana died aged 36 following a high-speed Paris car crash in August 1997, prompting an unprecedented outpouring of public grief.