It turned out to be a terrible decision, but Diana, Princess of Wales, chose to spend her final summer in the company of the Fayedeen - billionaire businessman Mohamed Fayed's retinue of family, staff, PR and security - in Fayed boats, apartments and hotels. Having been invited on holiday with the Harrods boss, Diana started her relationship with his son, Dodi, in July 1997.
Unbeknown to her, Dodi was at the time holidaying with his American fiancée, Kelly Fisher - a Calvin Klein model. Dodi was sleeping with Kelly on one of the Fayed boats, while courting Diana on another - the Jonikal, a 150ft luxury yacht Mohamed had bought specifically to entertain the Princess. It was only six weeks after they met that Diana and Dodi were killed in a fatal Paris car crash.
Mohamed Fayed has since spent tens of millions of pounds attempting to expunge the Fayed name from the following sequence of events.
When she died, Diana was travelling from a Fayed hotel to a Fayed apartment. She was in a Fayed car, sitting next to Fayed's son and heir, Dodi. The driver, Henri Paul, was not a chauffeur.
He was the acting head of the Hôtel Ritz Paris security who had been recalled from an evening off by the Fayeds - father and son - to return Diana and Dodi to the Arsène Houssaye apartment - their luxury accommodation just off the Champs-Élysées.
In over a decade of Ritz service, Paul had never driven any member of the Fayed family anywhere, ever. Neither Fayed had any reason to believe that Paul had been drinking. Nor did the two Fayed bodyguards, who were responsible for the couple's safety.
A sad irony of Diana's last journey was that chauffeurs Philippe Dourneau and Jean-François Musa, who had driven the couple to the Ritz for their last meal, had been waiting for them at the front of the hotel.
No qualified French chauffeur has ever been involved in a fatal accident. Dourneau and Musa later made their way to the Alma-tunnel crash site, and were devastated to discover that Paul had been at the wheel.
This day was a most significant one for Diana - exactly one year earlier she had been divorced from the Prince of Wales. She toasted the moment in champagne with Dodi on the Jonikal.
The following evening, the couple celebrated with a barbecue on a small beach in Sardinia. According to their butler, Rene Delorme, this was one of the most romantic nights of their summer together. Dressed in an evening suit and bow tie, he served them with caviar.
The Jonikal's chef prepared barbecued chicken burgers, pork and smoked sausages. The next day, they flew from Olbia in Sardinia to Paris. The couple - and their Fayed bodyguards, Kes Wingfield and Trevor Rees-Jones - touched down at Le Bourget airport at lunchtime.
Close friends say that Diana had been reluctant to go to Paris, and wanted to go straight home to see her sons. Her summer with Dodi was at an end, but he had insisted on a final flourish in Paris, where some of his family's proudest possessions are to be found.
Unsurprisingly, their flight was met by the paparazzi, and the final pursuit of Diana then began. The Fayed PR team had made the most of the Diana factor since 'The Kiss' picture in the Sunday Mirror in August had alerted the world to the romance. PR supremo Max Clifford told me that even he had been made aware of Dodi's intention to visit Paris before returning to the UK.
As soon as they got into their limousine at the airport, driven by Dodi's personal chauffeur, Dourneau, they were chased by paparazzi on motorbikes. Dodi was upset by this and instructed Dourneau to drive fast to try to lose them.
Princess Diana was also upset. Dourneau recalls her screaming at him to "slow down" so he would not hit a photographer as they hurtled around the périphérique. The seasoned chauffeur managed to lose the paparazzi altogether with a deft manouevre to exit the Paris ring road.
His task was made easier as no one had any idea where Dodi was taking the Princess. According to Dourneau, Diana was trying to soothe his boss during their journey. 'Don't worry Dodi,' he recalls her saying, as she placed a hand on his knee.
30 AUGUST 1997 - 15:45
Their first destination was the Villa Windsor, which Mohamed Fayed has rented from the Paris authorities for decades. (It is thought unlikely that Dodi told Diana that the previous month he had given his then fiancée, Kelly Fisher, an identical tour.)
The villa is the former home of the exiled King Edward VIII and his American wife, Wallis Simpson - the Duke and Duchess of Windsor. It lies in the Bois de Boulogne on the edge of Paris. Although Diana told friends that she was "blissfully happy", while she was in Paris she did not enjoy the Villa Windsor visit.
Later that afternoon, she confided in one journalist that "it has a history and ghosts of its own and I have no wish to follow that".
They then went to the Ritz. Diana would have been familiar with the hotel as the couple had visited it secretly for a brief stay in July. Claude Roulet, assistant to the president of the Ritz, welcomed them. He was also a historian who was writing a book about the hotel. He remembers asking Diana if he should address her as "Lady Dee" - as most French people called her. Placing her hand on his arm, she told him, "Just call me Di."
While Diana had her hair done by a Ritz stylist, Dodi visited the jeweller Repossi in the Place Vendôme. Although only 80 metres from the Ritz, Dodi instructed Dourneau to drive him there.
He emerged with only a brochure, but he had arranged purchase of what was to become a controversial gold and diamond ring. After the couple died, Mohamed Fayed claimed that it was an engagement ring, as did Alberto Repossi himself.
Roulet accompanied Dodi to the jewellers. He does not recall either man mentioning "engagement" as the ring was selected. Roulet later collected it. When he gave it to Dodi, he asked if he intended to give the ring to Diana that night. Dodi said he did not know. There is no evidence that Diana ever saw the ring. It was later recovered from the Fayed apartment on rue Arsène Houssaye.
Mohamed Fayed paid for the ring after the couple died. It was later put on display in Harrods. Despite the fact that there was no evidence to support the claim, it was described as the couple's "engagement ring".
After leaving the Ritz, the couple spent a couple of hours in the Arsène Houssaye apartment until two Fayed vehicles arrived to collect them and take them to the trendy Chez Benoit restaurant, where Claude Roulet had booked a table for them (in his own name) and was awaiting their arrival.
However, dozens of paparazzi had gathered outside the apartment; an agency had already put their pictures (from their arrival at Le Bourget) on the wires and word was out. The presence of the same two cars outside - one driven by Dourneau, which would take the couple, and the other by Jean-Francois Musa for the bodyguards - indicated that departure was imminent.
As soon as their car moved off, the paps behaved like real devils
Bodyguard Kes Wingfield remembers the chaotic scenes outside the Arsène Houssaye apartment. "As soon as their car moved off, the paps behaved like real devils. They called for their bikes and sped off like fools, trying to stick to the car. They could have knocked over pedestrians. People flattened themselves against walls as their bikes mounted the pavements and sped past."
"They were all around us," recalls Dourneau. "At the sides, in front, behind. Some acted as scouts, riding ahead of us to find out where we were going."
Unfamiliar with being pursued like this, a furious Dodi ditched his Chez Benoit idea en route. He told Dourneau to head for the protection of the Ritz. The photographers would not be able to get in and the couple could regain some privacy after the shambles of their apartment exit.
Dodi chose to blame the bodyguards for what he described as the 'f- up' of their final journey. The bodyguards countered by telling Dodi that it had been impossible for them to prepare for it, as they had no idea that the hotel would be their destination.
They had thought they were going to Chez Benoit. The couple were last seen on the hotel's CCTV. Despite the photographers' best efforts, they failed to get a single picture of the Diana and Dodi out together in Paris.
Diana looked disconsolate as she entered the Ritz for the last time. The couple went straight to the L'Espadon restaurant. They ordered food but Diana was clearly upset. Fellow diners reported that they saw her crying as she ordered before they decamped to the Imperial Suite for their final meal to be served.
CCTV later captured Dodi emerging from the suite and talking to the bodyguards around midnight. He told them that he had devised a plan to evade the paparazzi when they left the hotel. It was in this conversation that his and Diana's fates were sealed.
Dodi's 'plan' was to leave the Ritz with Diana by the rear entrance. He had asked staff to whistle up another Mercedes which, he told the bodyguards, would be driven by Henri Paul. Wingfield and Rees-Jones, said Dodi, were not to accompany them.
It was the best "plan" Dodi had ever come up with. And it were crap
Their role would be to "create a diversion" by taking the two limousines from the front of the hotel. Both bodyguards strongly objected to the idea of Diana being allowed to leave the hotel without security. And neither man believed they would be best deployed as decoys.
Dodi countered by saying that his plan had been "OK'd with MF" - which meant "my father", Mohamed Fayed. All now knew the argument was over. MF called the shots in the Ritz, as he had throughout the couple's French holiday.
Wingfield, a plain-speaking Yorkshireman, later told me, "It was the best 'plan' Dodi had ever come up with. And it were crap."
Fayed himself has given several different versions of this final conversation with Dodi. Characteristically all his versions omit mention of Henri Paul, or his own responsibility for standing down Dourneau and Musa, the regular Fayed chauffeurs, who were awaiting the couple at the front of the Ritz.
31 AUGUST 1997 - 00:18
Whatever the content of the final Fayed family conversation, another Mercedes appeared at the back of the Ritz. Diana, Dodi and Henri Paul are captured on CCTV waiting, and then leaving at 12.18am. Because of the bodyguards' objections, Dodi had agreed to take one of them: Trevor Rees-Jones.
Five minutes later, Henri Paul drove the Mercedes into pillar 13 of the Place l'Alma underpass and died instantly, as did Dodi Fayed. Trevor Rees-Jones was to be the only survivor despite savage injuries. None of them had been wearing seatbelts.
Princess Diana was cut out of the car by the French emergency service SAMU. She had been critically injured and she had a heart attack at this time. Because her blood pressure was dangerously low she was driven extremely slowly to the Pitié-Salpêtrière Hospital. However, despite the best efforts of top emergency surgeons, Diana was declared dead at 4am.
In the French Investigation, Judge Hervé Stéphan concluded in his report that Henri Paul hit the pillar without touching the Mercedes' brakes, driving at between 61 and 63mph. (The speed limit is 30mph.) Paul was also drunk.
The French legal driving limit is 0.50 grams of alcohol per litre. Paul's blood samples showed he had a level of 1.74g/litre. Ritz bills indicated that he had drunk two pastis there, and it is thought that he must have been drinking prior to his return to the hotel.
At Paul's parents' request, a second set of tests were performed which were videotaped. The results were identical. The judge decided that none of the chasing photographers or paparazzi should be prosecuted.
Expert forensic analysis of white paint scrapes on the crashed Mercedes by technicians at the Institut de Recherche Criminelle de la Gendarmerie Nationale established that the Mercedes had brushed a white Fiat Uno immediately before the crash.
No one claimed to have seen the Fiat in the Alma tunnel at the time of the crash. However, witnesses later confirmed that they had seen an Uno exiting the tunnel. Despite a nationwide search, the Fiat was never found.
Before Diana's corpse had reached the Hammersmith and Fulham mortuary in London for its autopsy on 31 August 1997, Fayed had dispatched Ritz officials to French police to inform them that, as Dodi's father, he suspected "a conspiracy to murder" the couple.
The Ritz hotel president, Frank Klein, and his assistant, Claude Roulet, were tasked with transmitting this initial piece of fake news. Before the 2007 UK inquests, Fayed spent tens of millions of pounds in an apparent attempt to distance his family from any responsibility for Diana's death.
Headed by former Metropolitan police chief Sir John Stevens in 2006, Operation Paget was to investigate all of Fayed's 175 "conspiracy to murder" theories in the build-up to the inquest. Not one shred of credible evidence to support any of these charges was found.
The massive 832-page report, which appeared to redefine the meaning of the word "comprehensive", was definitive. At 500,000 words long, the report concluded that, "There was no conspiracy to murder any of the occupants of the car. This was a tragic accident."
Well-informed legal sources estimate that Fayed spent at least £50 million on the 2007/2008 London inquests into Diana and Dodi's deaths. He hired three of the UK's leading QCs, plus appropriate legal support to represent himself, his hotel and Henri Paul's parents.
However, Fayed himself was humiliated and ridiculed in the witness box. He scattered accusations of a vast plot to kill the couple encompassing British and French security, police, medical and judicial services as well as the Duke of Edinburgh, Tony Blair, his own bodyguards, even Henri Paul, without being able to produce evidence for any of them.
No one who was not an employee, in his pay or a client, gave support to his claims. Fayed told the inquest that he would accept the jury's finding. However, he then spent more millions producing a film, Unlawful Killing, about the deaths. (The film was never seen in the UK as Fayed's own lawyers reportedly advised 87 cuts would have to be made.)
A telling moment occurred mid-inquest when the coroner, Lord Justice Scott Baker, interrupted Fayed's QC, Michael Mansfield, and told him to "tether his allegations to evidence". He was concerned that the inquests, which eventually ran for six months, might never end.
Unable to achieve this, as there was no evidence to support his case, Mansfield told the court that the couple had been murdered in a criminal conspiracy by the British Establishment, allegedly led by the Duke of Edinburgh.
Eventually the QC and his client had to accept the jury's verdict. Princess Diana and Dodi Fayed had been "unlawfully killed" by "grossly negligent driving".
Neither bodyguard on duty that night in Paris had approved the security arrangements that were to kill the woman who became known, on the day she died, as the "People's Princess".
• Diana, The Last Days, by Martyn Gregory, is published by Virgin Books