The world thought that Diana had finally found true love with Dodi Fayed during the last summer of her life. But now, it turns out, there may be more to the story. Correspondent Richard Schlesinger reports.
"Marriage with Dodi Fayed was not in the cards. I'm absolutely certain of that," says author Kate Snell, who has a surprising theory on why photos of Dodi and Diana were taken and broadcast around the world just before her death.
Snell, who conducted extensive research and produced a documentary about Diana, says the princess wanted these pictures published to inspire jealousy in the man with whom she was really in love.
"Very near the end of her life, she said to one of her friends, 'I'm no longer lonely. I know what love is now,'" says Snell. "And I think that's the gift that one man gave her. And that one man was Dr. Hasnat Khan."
Khan, a cardiologist still practicing in London, has managed to avoid the flashbulbs and spotlights that dogged Diana incessantly.
But if Snell is right, the princess did indeed find the true love she had wanted all her life -- just before her death. "She was deeply insecure. She was a person constantly in search of love. That dominated her whole life," says Snell.
Diana's search for love almost always played out publicly, from the day of her marriage, which was probably doomed the day it began. Prince Charles invited his lover, Camilla Parker Bowles, to the wedding and Diana knew it.
"Her ideals were simple. She just wanted to do the very best she could, for the royal family. She wanted to strike out and do the very best she could as Diana, the Princess of Wales," says Ken Wharfe, who was in charge of security for Diana.
By the time Wharfe joined the palace guard, and became head of security, Diana's marriage was crumbling and she was deeply involved in her first affair with riding instructor James Hewitt.
"She said to me, 'Look, you may not know already, but you know I'm seeing a man called James Hewitt," says Wharfe. "And one didn't need to ask further questions."
Wharfe says he made no moral judgments about his boss, and that his job was keeping the princess safe and the affair secret. Hewitt's mother frequently invited the couple and Diana's bodyguards to her cottage on the English coast. The visits were always kept discreet, and allowed the couple a small taste of normalcy.
"We would use sort of beaches and woodland areas nearby," says Wharfe. "It was actually a normal weekend where two people could enjoy each other's company, you know, alone."
As the affair continued, Diana's security wasn't the only concern. Her image also had to be protected and that's what worried Diana's chief of staff, Patrick Jephson.
"It seemed that she had so much going for her that to risk losing it all for the sake of what could only ever have been an affair was a pretty high risk strategy," recalls Jephson, who says that he didn't ask Diana to stop. "I recognized that she wasn't a machine. She was a human being. And she as much as anyone - in fact, more than most people - deserved a bit of happiness in her love life."
Despite the growing strain between Diana and Charles, Jephson made sure their public appearances gave nothing away.
"I would have to arrange for them to arrive from separate places, but appear to arrive together, and their airplanes would arrive simultaneously at an airport, and then they would get into the same car and arrive in the city center together," says Jephson. "It was hard work."
After five years, Diana broke up with Hewitt, who was distraught and sought advice from Wharfe.
"I remember saying specifically to him, 'Well, look, you know, if it's over, I said, consider yourself to have been in a very privileged position,'" recalls Wharfe. "And I said, 'Really that's the end of it. Live with that memory.'"
Even while she was still married to Prince Charles and still seeing Hewitt, Diana had reportedly begun a romance with a third man, a car dealer named James Gilby.
Diana and Gilby sometimes had to settle for passionate phone conversations, despite warnings from Wharfe that cell phone calls were not always private. One of those conversations was recorded and ended up being played in public a few years later.
By early 1992, Diana surprised even her palace guard. She had a new relationship with married art dealer Oliver Hoare. One night, Diana drove up to the palace, and her trunk popped open. The officer on duty that night was shocked.
"He said, 'Well, sir, quite late last night, sir, the princess arrives home … and then the boot sprung or the trunk sprung, sir, and a man got out of the boot, sir,'" recalls Wharfe.
"I said, 'Are you serious?' And he said 'Absolutely serious.' He said, 'Well, we did recognize the man, sir, and he went inside, and left later that night.' But of course, I subsequently found out this was Mr. Oliver Hoare. And the princess and I had a discussion about it."
Wharfe and the princess worked out more conventional ways to get Hoare into the palace. But, Hoare's exits were occasionally awkward. Wharfe remembers one rude awakening early one morning by the palace smoke alarm.
"As I sort of went down to the ground floor, so the smell of cigar smoke became stronger and stronger. And then I found Mr. Hoare standing underneath this sort of decorative bay tree in the lobby of Kensington Palace, and unfortunately he couldn't get out because the door was locked and they were alarmed, but he was leaving the property," says Wharfe. "I said, effectively 'Good morning, Mr. Hoare,' and there was a suitable answer to that. I don't think anything more needed to be said."
Before long, evidence that the marriage had collapsed was hard to ignore, and the palace finally stopped pretending that Charles and Diana were still a royal couple.
But the end of the marriage was not the end of the problems in Diana's life. When Hoare broke off the relationship and returned to his wife, Diana reportedly made more than 300 nuisance calls to his home. Hoare called the police, who traced the calls to the princess.
This time, the palace guard couldn't protect her. "I do think that the drip, drip effect of embarrassing revelations about her private life had a corrosive effect on her public image," says Jephson.
At her exclusive London gym, Diana struck up a relationship with Will Carling, a rugby player who was very famous and very involved with a woman who was very tough and very angry. Carling got married and his wife wasn't going away without a fight.
"The difference with Will Carling was Mrs. Carling," says Jephson. "And I think with her, the princess found that she'd run up against an adversary who was younger than her, blonder than her, and in many ways, feistier than her."
Even though Carling denied the affair, the story became even more scandalous when the Carling's marriage broke up.
By 1994, Diana had separated from Prince Charles and was on her own.
She was lonely and vulnerable, but not for long. When a friend suddenly needed heart surgery, Diana rushed to his bedside. That's where she met Dr. Hasnat Khan.
Snell says that Diana couldn't wait to tell her friends about Hasnat:
"She said, 'Isn't he just drop-dead gorgeous?' … And she also described the meeting to one of her friends as being 'karmic ' -- that this was a man she felt was going to have an influence on her future and shape her destiny."
Diana was soon a fixture at the Royal Brompton Hospital, visiting patients, offering comfort, even watching a heart operation. She was spending a lot of time around Hasnat, the shy, quiet, doctor who now fascinated her.
"She admired his humanity, his compassion, and his utter devotion to the sick and the suffering," says Snell. "I think if a relationship was meaningful to Diana, she went out of her way to make sure it didn't reach the headlines. And she went to extraordinary lengths to keep it out of the press."
But they were two people from two different worlds.
"He's not interested in the money, he's not interested in the fame. I think he just loved her for being Diana," says Shekhar Bhatia, one of the few journalists who has actually talked to Hasnat Khan, who regularly refuses interview requests.
Hasnat came from a very conservative, educated family in Pakistan, and Diana decided she had to prove that she understood and respected his culture. So, in 1996 she went to Pakistan, and visited a cancer hospital run by a well-known cricket player and politician, Imran Khan -- who was also Hasnat's distant cousin.
After returning from Pakistan, Diana's divorce became official and she continued pursuing Hasnat Khan. Her friends have said she snuck him into Kensington Palace -- hiding him in the trunk of her car.
When the two went out, she reportedly wore disguises, so they could visit restaurants and clubs, just like a normal couple. But they weren't a normal couple, and never would be.
"I think he would have loved Diana to be the girl next door. I think what he couldn't cope with was the Princess of Wales, the mother of the future king, and all of the baggage that she brought with her," says Snell.
However, Hasnat also had problems with his parents. He was raised to believe in the tradition of arranged marriage, and a western, divorced non-Islamic woman would never get his parent's approval.
"They were still of the belief that he was gonna marry a girl of their choice," says Bhatia. "In his father's words, he will marry no one, nowhere, without my permission."
By 1997, their relationship stalled. Diana wanted to marry Hasnat, but he never proposed. So she turned to Imran Khan, one man she thought could understand. He had married a British aristocrat from outside the faith, so Diana asked him if he would intervene and convince Hasnat to do the same.
"Maybe I could speak to him, because having married someone from outside my culture, maybe there if there was something which could be cleared, if there was advice that could be given, maybe I would be able to help," says Imran Khan.
During this trip, Diana paid a low-key visit to Hasnat's family. She had already sent them letters, and she hoped to convince Hasnat's parents that she was the right woman for their son. But it didn't work.
"I don't think Diana had given up hoping that there could be a future. As far as Dr. Khan was concerned, he called the relationship off. But I don't believe Diana considered that was the end," says Snell.
Snell says their breakup happened just days before Diana's kiss with Dodi Fayed was seen around the world. But several people in a position to know now say it was Diana herself who arranged for the photographer to be there, to get just the right shots to make Hasnat jealous.
"She was not in love with Dodi. She was in love with Hasnat Khan," says Snell. "She wanted to get back to Kensington Palace. And she enjoyed being with Dodi, but when she got back home, Dodi would be a past chapter in her life."
As it turned out, Diana was already living the last chapter of her life. And to this day, Hasnat Khan has never spoken about the details of what happened between them. But Hasnat Khan was among the mourners at Diana's funeral at Westminster Abbey, unable to completely hide his emotions behind his dark glasses.