On 31 August 1997, Princess Diana died at the age of 36, after her intoxicated chauffeur crashed into the walls of the Pont de l’Alma tunnel whilst speeding away from paparazzi.

Ten days earlier, she’d turned to a close friend to make a gut-wrenching confession about her two sons, Princes William and Harry, lifting the lid on her most sincere ‘regret’.

The confidant in question was Rosa Monckton, with whom Diana holidayed with in Greece during the summer of 1997.

Little did the gal-pals know at the time, that the trip would mark the last they’d enjoy side-by-side.

Days before she and rumoured partner Dodi Fayed flew to Paris on their way back to London, Diana reportedly brought up to Monckton her notorious Panorama interview – during which she discussed her failing marriage, as well as her own and Prince Charles’ romantic affairs.

The bombshell conversation with the BBC sent shockwaves around the world at the time, given that the late Princess also opened up about her struggles with bulimia and postnatal depression.

Most alarmingly for the monarchy, however, were her explicit doubts about Charles’ suitability as King.

Apparently, however, Diana would come to regret the interview – which would reach over 200 million viewers worldwide – having miscalculated the impact that it would have on her sons.

William, 15, and Harry, 12, who were residing hundreds of miles away in London at the time.

Monckton told PEOPLE of the pair’s beachside conversation: “She told me she regretted doing it because of the harm she thought it had done to her boys.”

In the years following the interview, journalist Martin Bashir was found to have used forged documents and deception to secure access to Diana, with the BBC later covering up his dishonesty.

A 2021 inquiry led by Lord Dyson ruled that Bashir had told the mother-of-two that the conversation was the only means of having her say, and that her ex-husband had secretly planned to have her killed, citing false bank statements.

On this, Monckton recalled: “She was frail and that made her susceptible to Bashir.”

She added that Diana ‘kept it all in’, explaining: “He’d told her she couldn’t talk about it. She cut people out because of that.”

William, now 43, has also spoken out about Bashir’s lies, claiming his scheme only served to further fuel Diana’s ‘fear, paranoia and isolation’.

“She was failed not just by a rogue reporter but by leaders at the BBC who looked the other way rather than asking the tough questions,” he previously hit out.

“These failings – not only let my mother down and my family down; they let the public down too.”

Prince Harry voiced similar sentiments in 2021, telling press of the interview: “Our mother lost her life because of this.”