THE WORLD THOUGHT THEY KNEW PRINCESS DIANA, NOW 20 YEARS LATER VIEWERS LEARN WHO SHE REALLY WAS, IN CBS NEWS' "PRINCESS DIANA: HER LIFE | HER DEATH | THE TRUTH"

MONDAY, MAY 22, 2017 8:00-10:00 PM, ET/PT

Princess Diana captured the world's imagination so much so, many thought they really knew her. The reality is that they just knew a part of the Diana story. CBS THIS MORNING co-host Gayle King explores the public and private life of the complex woman who died too soon, in PRINCESS DIANA: HER LIFE | HER DEATH | THE TRUTH, a two-hour primetime special to be broadcast Monday, May 22 (8:00-10:00 PM, ET/PT) on the CBS Television Network.

"Her name was Diana and the world fell in love with her," King says in the special. "But her fairy tale life also had a heartache - it did not have a happily ever after ending."

This summer it will be 20 years since the death of Diana, Princess of Wales. To mark the anniversary, King anchors the broadcast from Althorp, the Princesses' family estate in England. Through the words of those who knew her and admired her, in her own words, and through the rich archive of CBS News, the special looks at the impact Princess Diana had on Britain, the monarchy and the world. The special features interviews with close friends who open up about their personal conversations with Princess Diana in the weeks leading up to her death. In fact, friend Lana Marks reveals something surprising - the man who was the only one true love of her life.

From her wedding to Prince Charles in 1981 until her tragic death in a horrific car crash in the Pont de I'Alma road tunnel in Paris on August 31, 1997, Princess Diana was a public draw, but there was much more behind the headlines that most people never knew.

"I think Diana's death robbed the world of an extraordinary, luminous character," says author Patrick Jephson. "She leaves an unfillable gap on the world stage."

Behind the crown and the designer dresses, Diana was a complicated and occasionally unpredictable woman, say those who knew her best. "She always said, 'I want to be normal,'" says Ken Wharfe, her former bodyguard. "The tragedy is, with being a member of the royal family, it's almost impossible to be normal."

She was far from normal. In fact, the marriage that captured the hearts of people around the world was a struggle. In public they played their parts, but in private it was a different story. "They would fight," says author Sally Bedell Smith, "and she would taunt Prince Charles by telling him he'd never be king."

"And there was one moment when they were having a big fight, and he was down on his knees praying, and Diana was hitting him even as he was praying," Bedell Smith says. "That was the kind of intensity of the discord that they had."

Just as the world watched Prince Charles and Diana married, they watched as the marriage unraveled. They also followed along as Princess Diana reemerged in public life alone after the divorce and right up until she died. At the time, the summer of 1997 was supposed to be a time of self-discovery and new beginnings. She was no longer a member of the royal family and was dating businessman Dodi Al Fayed. It all ended when they piled into a Mercedes and sped off from the Ritz hotel in Paris with paparazzi chasing them.

When the Mercedes reached the Pont de I'Alma road tunnel, driver Henri Paul lost control. He sideswiped a slower moving white Fiat that drove off.

Her death was just as controversial as her life. Almost immediately conspiracy theories were raised about what happened. Were the paparazzi somehow responsible? Had someone tampered with the Mercedes? What about that white Fiat? Did the driver intentionally cause the crash? And what could have been done to prevent the crash?

At Buckingham Palace, Princess Diana's former home, the flag did not immediately fly at half mast, raising even more questions.

The two-hour special, produced by the team at 48 HOURS, also takes viewers on a journey through the four independent investigations in two separate countries that followed. The broadcast examines each of the theories and finally puts to rest what really happened the night she was killed in a car crash.

"It was just not the kind of ending one would have expected for anyone, let alone Diana," says Ingrid Seward, editor of Majesty Magazine.

PRINCESS DIANA: HER LIFE | HER DEATH | THE TRUTH also features interviews with journalist Richard Kay, writer Peter York, Diana's friend and employer Mary Robertson, historian David Starkey, dancer Wayne Sleep and others.

PRINCESS DIANA: HER LIFE | HER DEATH | THE TRUTH is produced by Chris Ritzen, Ruth Chenetz, Liza Finley, Jamie Stolz and Anthony Venditti. Lauren Clark, Charlotte Fuller, Stephen A. McCain and Stephanie Slifer are the field producers. Simon Downs, Simon Ellory, Delphine Reau, Isabel Marking, Charles Berkowitz, Dena Goldstein, Kayla Keddal, Lauren White, Brittany Morgan and Katie Fallon are the associate producers. Mead Stone is the producer-editor. Doreen Schechter, Michael Baluzy, Richard Barber, Atticus Brady, Ken Blum, Michael McHugh, Gregory F. McLaughlin, Diana Modica and Jason Schmidt are the editors. Deb Thomson, Andy Clarke and Paolo Marenghi are the senior producers in London. Jerry Cipriano is the writer. Patti Aronofsky is the senior broadcast producer. Rob Klug is the director. Anthony Batson is the senior broadcast producer. Susan Zirinsky is the senior executive producer.

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