What really happened here?

"The Crown," which has been telling the long story of Queen Elizabeth II's reign since 2016, is a dramatic and fictional interpretation of history. It's full of invention and supposition, the educated guesses of creator Peter Morgan about what happened in the private lives of the British royal family for over half a century. But it leaves viewers dying to know what really happened behind the palace walls.

In fact, watching Part 1 of Netflix's final season (now streaming) might leave you with a bevy of questions. Four new episodes, set in 1997 in the weeks leading up to the death of Princess Diana (Elizabeth Debicki), zoom in on the private life of the People's Princess after her divorce from Prince Charles (Dominic West). They focus primarily on her relationship with Harrods heir Dodi Fayed (Khalid Abdalla), who died with her in a car crash in Paris in August 1997.

But what part of the story "The Crown" tells actually happened? Did Dodi really propose to Diana on the day of the crash? Did Dodi's father Mohamed (Salim Daw) really push them together and call the paparazzi on them? And did Diana's death really bring the world to a standstill?

To separate fact from fiction, USA TOAY spoke with Hugo Vickers, the historian and biographer who has literally written the book on the royals, as well as Debicki and Abdalla, who explain how they researched the love affair they portrayed.

Did Dodi Fayed really leave his fiancé just before their wedding because of Diana?

When Diana and Dodi began their initial relationship, he was engaged to American model Kelly Fisher (Erin Richards). He broke off their engagement to pursue Diana, and it had major consequences, as the show portrays. "She tried to sue him," Vickers says. It generated "a lot of publicity." But "she dropped the case when he was killed."

Was Charles secretly campaigning for Camilla’s legitimacy while Diana was still alive?

The first episode of the new season shows Charles working hard to get positive press coverage of his long love Camilla Parker Bowles (Olivia Williams). He also tries to convince his mother, Queen Elizabeth II (Imelda Staunton), to legitimize Camilla as his partner by attending her birthday party, which Elizabeth refuses to do. Vickers says Charles was "definitely trying to put Camilla on the map" and increase her popularity in the country. However, "the so-called campaign was somewhat put on hold after Diana’s death."

Did Mohamed Al-Fayed really summon the paparazzi to take the infamous photos of Dodi and Diana kissing?

It's hard to know exactly how photographer Mario Brenna learned that Diana and Dodi were vacationing together on the Fayeds' yacht in Monte Carlo when he took the infamous photos of them kissing, embracing and sunbathing. Vickers can only surmise, based on the behavior of Mohamed Al-Fayed at the time, that he might have. "He certainly did similar things. Hard to know the exact details. But he was using Diana, no question of that."

The photos led to a bidding war, and the international sensation the show portrays. It was "massive," says Vickers. A 10-page spread of photos was published in the Sunday Mirror on August 10. Brenna and his partner made more than $2 million from them.

Did Charles scheme with his publicist to do a ‘counter photo’ with the boys?

There were photos of Prince Charles, Prince WIlliam (Rufus Kampa) and Prince Harry (Fflyn Edwards) taken at Balmoral in August 1997, but they didn't happen exactly as the show portrays. "Tim Graham, a well known photographer, took those photos on August 16," Vickers says, and not the small-time Scottish photographer the series invents. The photos also weren't quite as out-of-character for either Charles' family or other royals when they were at Balmoral, as the show portrays. The royals routinely had planned photo shoots at the estate while on vacation, and still do.

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The show implies Dodi had spurious motives courting Diana, egged on by his father. How much do we know about that?

Mohamed Fayed bought the yacht Jonikal especially to entertain Diana, Vickers says. "The motives were rather as shown: ensnaring Diana." It's impossible to know Dodi's personal motives or feelings.

Abdalla and Debicki say they studied hundreds of photographs and hours of surveillance footage of Dodi and Diana on the day of the crash. They watched it all, "second by second, minute by minute," Abdalla says. "You see this incredibly tender hand hold behind their backs and their heads nuzzled against each other and very gentle caressing, for seven minutes. And from that you understand the tenderness of a certain kind of falling in love."

Did Dodi propose to Diana in Paris on the day of the crash?

In the series, Dodi makes Diana stop in Paris (on the trip where they would soon die) to buy an engagement ring he thinks she wants. He then proposes to her, but she says no.

"It is said he bought a ring," Vickers says, but "she was not going to marry him." A 1998 book by Time magazine correspondents Tom Sancton and Scott MacLeod about Diana's death suggests that Dodi planned to propose. At an inquest in 2007, evidence was presented that Dodi went to the Repossi shop on the Place Vendôme in Paris on August 30 and purchased a diamond ring.

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In 'The Crown,' Diana and Dodi’s driver has several drinks in the hours leading up to the crash. Is that true?

"He did," Vickers says. Other investigations into the crash found that their driver, Henri Paul (Yoann Blanc), who also died in the crash, had two drinks at the Ritz hotel, where the couple was hanging out just before the crash.