Inside Princess Diana and JFK Jr's secret meeting that fueled romance rumors for decades

In December 1995, the world's two most famous people met in secret at New York City's Carlyle Hotel.

John F. Kennedy Jr. hoped to persuade Princess Diana to grace the cover of his magazine, George. The Princess of Wales, for her part, wanted to meet the man who had managed the impossible: living under an unforgiving media spotlight without being consumed by it.

Caroline Hallemann wrote about the encounter in her book, "The Kennedys & the Windsors," which explores the two dynasties and how their paths crossed over the years.

PRINCESS DIANA, HOT DOGS AND A PRESIDENTIAL MATCHMAKING ATTEMPT: ICONIC ROYAL VISITS TO AMERICA

"It was this clandestine meeting, and they were able to keep it a secret," Hallemann told Fox News Digital. "They were both hounded by paparazzi throughout their lives. That's something they had to deal with, but they were able to maintain privacy around this moment."

"I spoke with Patrick Jephson, who was Princess Diana's private secretary at the time, and I spoke with Rosemarie Terenzio, who was JFK Jr.'s executive assistant at ‘George’ magazine, to hear about what happened in this meeting," she shared. "Patrick was actually in the room when they met."

Hallemann wrote that while Kennedy was "excited" to meet the royal, he was also "annoyed about everybody hinting that this would be a marriage made in heaven if they could be together."

WATCH: JKF JR.'S SECRET MEETING WITH PRINCESS DIANA REVEALED

At the time, Kennedy was considered the world's most eligible bachelor. But for Diana, who had officially divorced then-Prince Charles, the meeting was purely professional.

"Patrick shared that this was really a business meeting," said Hallemann. "[Kennedy] thought that she quintessentially represented what the magazine was trying to achieve, which was to focus on the intersection of popular culture, politics and celebrity. And Princess Diana, from the start of the meeting, knew that she was going to say no, but she still wanted to meet with him anyway, which I think is quite telling."

Kennedy and Diana had met before, the book revealed. About a decade earlier, they both attended a luncheon in Virginia during the 1985 royal visit to Washington, D.C.

"She has the most unusual upward glance, really seductive," Kennedy told his friend Billy Noonan, adding that she had "the most unusual blue eyes," Hallemann wrote.

As for Diana, she was "keen" on the idea of spending time with Kennedy away from cameras.

"[His mother] Jackie Kennedy was a role model for Princess Diana in terms of how Jackie was able to raise her children in the public eye," Hallemann explained. "And I think that Princess Diana wanted to meet with John Jr. just to see how he managed life in the public eye."

CLICK HERE TO SIGN UP FOR THE ENTERTAINMENT NEWSLETTER

At first, it was suggested that Kennedy would wear a disguise to throw off the paparazzi. But Kennedy told friends, "I'm not going anywhere in disguise; that's the stupidest thing ever." 

The hotel's discretion was described as "extraordinary," Hallemann wrote. Kennedy had lived there following his father's assassination, and it was also a favorite of Diana's whenever she was in New York.

When Kennedy came face to face with the princess, he appeared "nervous."

"He was quite in awe of her," Jephson told Hallemann. "Not uncomfortable, but he certainly seemed to be on his best behavior." Diana was "very cool — and jolly, you know, and smiley and welcoming."

Hallemann told Fox News Digital the pair "spoke about a number of things," including Mother Teresa and the paparazzi.

"But ultimately, for John, the goal of this meeting was for Diana to be featured in ‘George’ magazine," she said. "Sadly, he walked away disappointed in that regard."

After giving Jephson "a sly glance," Diana told Kennedy that she would perhaps consider appearing in the 50th or 100th issue. Her decision was final. Still, the two spent "an hour or so together" talking.

LIKE WHAT YOU’RE READING? CLICK HERE FOR MORE ENTERTAINMENT NEWS

Later, rumors claimed Kennedy and Diana had an affair that was consummated at the Carlyle that day in a "moment of pure lust." Jephson told Hallemann he was in the room the entire time.

"I stayed in the room throughout and was not aware of any mad, passionate activities," he said. "My observation was that it was a kind of mutual sounding out. It was a kind of appraisal, and it wasn't overtly flirtatious, but it was friendly."

While Kennedy didn't get the answer he was hoping for, Diana left a lasting impression.

"I think he was charmed by her," said Hallemann. "He thought she was quite beautiful. There's one quote that's repeated by several people who spoke to him about her. [He] said she had great legs. I think he thought she was attractive."

"But it was really a business meeting — for him it was," said Hallemann. "It wasn't a social call, and he was really hopeful and saw the value she might bring by appearing in the magazine, and that element didn't work out."

According to the book, Diana wrote Kennedy a note. It read, "Thank you so much, but not right now." Again, she agreed to appear on a future cover.

Kennedy never gave up on the idea. The book describes how he quietly stayed in touch with Diana, asking her for an interview more than once.

In February 1997, she wrote him a letter saying she had to "regrettably" turn down his offer once more. She wrote, "'I hope"—with "hope" underlined—'"that the media are leaving both of you and [your wife] Carolyn alone. I know how difficult it is, but believe it or not, the worst paparazzi are here in Europe!"

On Aug. 31, 1997, Diana died from injuries sustained in a Paris car crash. She was 36. At the time, she was riding in a car that was being pursued by paparazzi.

"Princess Diana's death affected JFK Jr.," said Hallemann. "He saw a real similarity between them. He saw how much media interest and scrutiny there was, and he saw the role the media had played in her death. It worried him."

"In particular, it worried him because of the way his wife reacted to it," Hallemann continued. "Carolyn was deeply upset by Princess Diana's death. She was deeply rattled by her own experience with the paparazzi and also by the way Princess Diana died. She was already struggling with her relationship with the media, and this only took it one step further."

Kennedy and his wife, Carolyn Bessette Kennedy, died in a plane crash less than two years later, on July 16, 1999.

LAST PERSON TO SEE JFK JR. ALIVE REVEALS CHILLING PREMONITION ABOUT HIS FATAL FLIGHT THAT NIGHT

"I think that when people die young, they are mythologized in a way, and they are canonized in a way," said Hallemann. "For both Princess Diana and JFK Jr., these were two people who lived under enormous media scrutiny. They did a great deal of good, but they were also just people. And for one moment, they came together away from the spotlight."