Diana 1961-1997: The fateful decisions - Stalked, chased, frustrated, then devastated: her last day on earth

It began with paparazzi in Sardinia and ended in a hospital named Pity. John Lichfield in Paris traces the trail

The story begins with two lovers swimming beside a yacht in the Mediterranean off the coast of Sardinia and ends in a soulless, concrete underpass beside the Seine, 100 yards from the headquarters of Bateaux Mouches.

At the beginning, and at the end, there were the photographers. In Diana's life for the last 16 years, there were always the photographers, or paparazzi, as they are called (though not all the photographers involved were ruthless star-chasers).

In between - between Sardinia and the Pont d'Alma - there were 14 hours of fateful decisions by Dodi Fayed and Princess Diana and their companions.

Why, if they wanted to escape the paparazzi, did they go to the paparazzi capital of the world? Why put their heads into the hornets' nest? Why, if they wanted to shake off their pursuers did they go to the Ritz Hotel which is owned by Dodi's father, surely the most obvious place for the pack to wait? Why did the Ritz deputy security chief agree to drive even though he had been drinking heavily? Why did they make such a melodramatic escape anyway? They must have known that paparazzi were staking out the other Al Fayed addresses in Paris: the Duke of Windsor's former home, Dodi's flat in the Rue Arsene Houssaye.

The only person living who can definitively explain their actions is recovering from horrific injuries in the hospital Pitie Salpetriere. Trevor Rees-Jones, Dodi Fayed's bodyguard, may never be able to speak to police: the accident smashed his jaw and severed his tongue. He also suffered brain injuries. Officially, the hospital says that he will not be able to talk to investigators for several weeks; unofficially, hospital sources say that, even when he fully recovers consciousness, he may recall little of what happened that day.

The events in Paris on the night of Saturday 30-Sunday 31 August 1997 will be told and retold, examined and re-examined, distorted and re-distorted, as much as the events in Dallas on 22 November 1963. The raw facts are still being established by the French police, led by the examining magistrate, Herve Stephan, 43, who has a reputation as a calm, painstaking, independent- minded man. Some, possibly vital, details remain obscure. Was there anything wrong with the car? Apparently not, but it is still being checked. Why did the driver try to brake 50ft before the crash? Was there another car in his way, as new evidence suggests, or did he realise that he was losing control as the road dropped and turned awkwardly into the underpass?

Despite the manslaughter investigations started against six photographers and a despatch rider last week, police believe that there is no reliable evidence that the bike-riding paparazzi directly caused the crash. The claim by a British forensic scientist that the drink-driving evidence is "flawed" is dismissed contemptuously, even angrily, by the French authorities. "There have been drink-driving cases in France before," said one official close to the inquiry.

The weight of evidence in the 350-page preliminary police dossier suggests that the immediate cause was driver error. The Mercedes was being driven triply illegally: by a man who had drunk three to four times the legal limit of alcohol; was travelling at three times the speed limit; and did not have the required permit to drive a heavy and powerful limousine.

The behaviour of some photographers after the accident was appalling. Their behaviour before the accident was harassing and intrusive but no more so than on a thousand previous occasions. It seems that the decisions that made the fatal difference on Saturday 30 August were made - knowingly or unknowingly - by Dodi, Diana and their driver.

ON the Saturday morning, Diana and Dodi were still on the Fayed yacht Jonikal, where they had been three times in the past four weeks. They were spotted taking a morning bathe off the Sardinian coast by two Italian paparazzi in a motorised rubber dinghy. Did the lovers then decide to cut short their holiday by a day and flee the attentions of the paparazzi and hide away in Paris? This is one version of events. But Paris is the last place you would choose if you wanted to flee the paparazzi. It is the home of some of the most ferociously obstinate and resourceful star- chasers in the world. It is also the base of several of the world's best picture agencies, Gamma, Sygma and Sipa, who get 40 to 50 per cent of their income from door-stepping the famous.

In any case, it is now known that Dodi Fayed had a good reason to persuade Diana to end their holiday in Paris. He wanted to collect a ring that he had ordered from a shop in Monte Carlo 10 days before. He planned to give it to Diana at dinner.

At 1.30pm or thereabouts, Diana and Dodi were snapped flying out from Olbia airport in the northern part of Sardinia. But where were they going? Photo agencies in Paris say that they received a tip-off from British tabloid newspapers that it may be Paris. Indeed, it was. The couple were photographed at 3.20 that afternoon - Dodi in black, Diana in a fawn jacket, black top and white slacks - stepping from a Gulfstream jet owned by the Fayeds at Le Bourget airport.

They were met in a Range Rover by a balding man in glasses and a grey suit. His name was Henri Paul, the 41-year-old deputy head of security at the Ritz hotel. The couple drove into Paris in another car, a Mercedes, driven by a Ritz chauffeur, Philippe Journot. The Fayed family claimed later that the convoy was harassed by paparazzi on bikes and by a mysterious dark car, which tried to cut in front and slow them down.

Paparazzi swarmed like bees at all the obvious destinations for the couple in Paris. Dodi and Diana went to the Villa Windsor, where, according to the Fayed account, Diana was given a "guided tour of the house and garden". They drove on to the Ritz and entered by the rear door to avoid the posse outside.

They were sighted emerging from the Ritz at around 7pm and were driven towards the Champs Elysees. One account says they intended to go shopping. The version given to police by staff at the Ritz says they went to Dodi's bachelor hideaway at Rue Arsene Houssaye, where his American butler was already installed. They emerged soon after 9.30pm, intending to have dinner at a small, fashionable restaurant, Benoit in the Rue Saint Martin, in the centre of the city. Ritz staff say Dodi changed his mind when he saw the paparazzi in pursuit; he ordered the chauffeur - not Mr Paul at this stage - to return to the Ritz. The lovers had to push through a crowd of photographers to enter the hotel.

At some time that afternoon, Dodi dodged the photographers and went to Alberto Repossi's jewellery store on the other side of the Place Vendome to the Ritz. He collected the pounds 130,000 ring which the princess had chosen from the sister shop in Monte Carlo - diamonds in a star setting. Was it an engagement ring? The brand of rings, called "Say Yes to Me," was certainly promoted for that purpose. They had been advertised in the French glossies with the slogan: "A little yes, for the most wonderful day of your life."

BACK at the Ritz, the couple asked originally to dine in a private room, off the main restaurant, the Espadon, which has two Michelin stars. Later, becoming even more concerned for privacy, they switched to a private suite on the first floor. During the evening, Dodi spoke by internal phone to a Saudi cousin, Hussein Yassin, who happened to be staying in the hotel. Mr Yassin said Dodi's mood was "happy and elated." Questioned on his intentions towards Diana, he said: "We are very serious... we are going to get married."

Just after 10, Dodi Fayed - perhaps wishing to show off to Diana his ability to handle these things, especially in his father's hotel - devised a ruse to allow them to give the photographers the slip. Staff at the Ritz told investigators the plan was actually Mr Paul's; other staff told the French press it was Dodi's idea. On this point and others, Judge Stephan is said to be dissatisfied with the level of co-operation from the Ritz. Sources close to the investigation have spoken of a "halo of mystery" surrounding many of the decisions and events at the hotel that night.

It was decided that the Range Rover and Mercedes seen at Le Bourget would depart at speed from the front of the hotel with their usual chauffeurs. Diana and Dodi and their bodyguard would leave from the back entrance in the Rue Cambon in a Mercedes leased from Etoile Limousines, a small agency often used by the hotel. Mr Paul had left the hotel two hours earlier but was told to be on call. He came back to the Ritz just after 10pm and, according to Ritz staff interviewed by the police - and a close-circuit TV tape released later - showed no obvious signs of drunkenness: he walked normally; his breath did not smell of alcohol.

Mr Paul had been with the Ritz for 11 years. He was by all accounts well liked, although one anonymous colleague said last week that he was a man who "tried to do too much". Of his drinking habits, there were a wide range of accounts last week. He was sometimes "drunk as a pig," said one Ritz employee quoted in Liberation. Others said he was a moderate drinker; still others that he was on the wagon. Whatever his colleagues may have thought, it is believed by the French prosecutors that Mr Paul did drink - heavily - while he was away from the hotel that night. According to two tests conducted by police, and then an independent laboratory, he had between 175 and 187 mg of alcohol in every 100ml of blood, equivalent to well over a bottle of wine or, in terms of his favourite drink - Chivas Regal - six glasses of whisky.

There was something else about Mr Paul: he was a liar. He had misled his employers about his military record, saying that he left the air force in 1984 as a captain in charge of security at a base at Rochefort on the Bay of Biscay. The French military press office contradicted him posthumously. He had been an officer cadet during his national service in 1979. He had never been commissioned but was a lieutenant in the reserves.

According to Ritz employees who talked to the French press, Dodi Fayed asked Mr Paul to drive the the getaway car and he agreed. According to police interviews with Ritz senior staff, Mr Paul offered to drive. He was not a professional chauffeur but he had been on specialist driving courses with Mercedes in Germany. He often drove VIPs in limousines for the Ritz. If so he did it illegally. To drive a powerful limousine in Paris - une voiture de grande remise - you must have a special licence from the Prefecture de Police. Mr Paul did not.

Just after midnight, the decoy cars sped away from the front of the Ritz, taking some photographers with them. A few minutes later, the black armour- plated Mercedes S280, registration number 688 LTV 75, shot from the back entrance in the Rue Cambon. Mr Paul was driving with Trevor Rees-Jones in the right-hand front passenger seat; Dodi was in the back seat behind Mr Paul, Diana was to his right.

The ruse - a fairly transparent one - had not worked. Other photographers were staking out the Rue Cambon. According to their evidence to police, Mr Paul shouted at them, as he flashed by, words to the effect of: "You won't catch me". This is hard to believe: if he was attempting to escape unseen, why should he draw attention to himself? According to one of the photographers - one of seven detained later by the police - the challenge was issued somewhat later, when the Mercedes stopped at a red light in the Place de la Concorde.

A group of half a dozen paparazzi on motor-cycles gave chase. The limousine had to negotiate a crowded Rue de Rivoli before entering the Concorde. At this point in the chase, the claim by the Fayeds' spokesman, Michael Cole, that the bikers swarmed around the car like "Apache Indians surrounding a stagecoach" may have been accurate enough. Pictures taken by the paparazzi and developed later by the police included close-up shots of the car,

with an agitated Dodi and Princess Diana in the back.

Mr Paul, like many Parisian drivers, accelerated just before the lights turned green. He turned on to the faster roads along the right bank of the Seine heading west, very rapidly indeed. The pursuing photographers insist that by the time he had entered the Cours Albert Premier, half- a-mile away, they had been scattered 100 or 200 yards behind. A number of witnesses backed up their story. Several other witnesses told the police that they had seen bikes surrounding the car, even zig-zagging in front of the car, at this stage of the chase. If true, this would directly inculpate the press bikers in the disaster which followed.

The police and the prosecutors' office - who were, it should be remembered, trying to assemble evidence for a possible manslaughter charge against the paparazzi - studied the evidence from these witnesses carefully and rejected it. The 350-page dossier handed over to the examining magistrate on Tuesday accepts, in effect, the photographers' word on this crucial point.

WHERE was Mr Paul going? The Fayeds have a villa on the Rue Lauriston in the 16th arrondissement; they are also leasing the Duke and Duchess of Windsor's former mansion beside the Bois de Boulogne. Both could have been reached in the direction the Mercedes was heading. But the investigation, based on evidence from Dodi Fayed's butler, believes that he was actually making for Dodi's flat, where the couple had been earlier in the day. If so, Mr Paul's plan was to shake off the paparazzi on the fast roads along the Seine and double back to the Champs Elysees.

In truth, as everyone in the Mercedes probably suspected, there were other photographers waiting at all these addresses. So why the ruses, and why drive so fast? It is difficult to avoid the conclusion that, as on many similar occasions, this was a game of cat and mouse which was being played by both sides.

What happened next remains unclear and will be one of the main points of Judge Stephan's investigation. Police have three possible explanations; the Fayed family have another. The first hypothesis being examined by the police is that Mr Paul came suddenly upon a slower-moving car and lost control as he swerved to avoid it. Tyre marks over 50ft at the entrance to the tunnel suggest he braked hard: a Mercedes S280 has anti-lock braking which should not leave marks of this kind. One motorist says he was overtaken by the Mercedes just before it entered the tunnel.

The other police theories are that Mr Paul misjudged his approach to the left-hand bend within the tunnel; or his speed was so excessive that the car wheels left the road as it hit an irregular dip in the carriageway.

The Fayed family allege that the dark car which harassed Dodi and Di on the way from the airport made an abrupt reappearance in front of their Mercedes at this point. A witness came forward who claimed to have seen a vehicle harassing the Mercedes with a press bike close beside, but investigators say they are not taking this seriously at present.

The one piece of clearly rogue information was a report from a police source that the speedometer of the Mercedes jammed after the crash at 120mph. In truth, the speedo stopped at zero. But the prosecution dossier does estimate the speed of impact at around 90-100mph, three times the legal limit.

The Mercedes hit one of the central reservation pillars in the tunnel, then another. It bounced against the wall on the other side, flipped over at least once and ended right side up, pointing the wrong way, with the theft alarm sounding. Only one person in the car, bodyguard Trevor Rees- Jones, was wearing a seat belt.

Dodi and Mr Paul, on the left side which took the first impact, were killed instantly. Dr Frederic Mailliez, a passer-by who was one of the first on the scene, said that he found Diana "hunched between the seats with her back to the door". She was "groaning and making movements with her hands". But her condition "did not seem desperate". Visible injuries were to the head, leg and arms. But the impact of stopping dead at 100mph had mortally damaged her internally, tearing a hole in her pulmonary vein.

EVEN before Dr Mailliez got there, it seems that several photographers had taken pictures of Princess Diana and the other victims in the car. Two of the first policemen on the scene wrote a report in which they described the attitude of the paparazzi as "malignant and obstructive", pushing aside emergency workers to get better shots. One photographer - later identified as Christian Martinez - shouted at the police: "You make me shit. Let me do my job. Even in Sarajevo the cops let you work."

Another photographer, Romuald Rat, admitted opening the car door and touching the bodies. He denied this was to move them for better shots,but said he was taking Diana's pulse to check whether she was alive. Other witnesses have told police that paparazzi moved the victims' arms, even heads to get better shots. At one point the photographers began to row among themselves about their behaviour.

Pictures taken in these chilling, crazy moments were offered to magazines and newspapers around the world within the hour. They were taken by three photographers who escaped from the scene but gave themselves up on Thursday. They showed Diana with both eyes open, looking "pretty", said the head of the agency which marketed them, Laurent Sola. "You would not think that she was going to die."

Diana was treated by Dr Mailliez and emergency workers. After an hour, she was freed from the car and taken to the Pitie Salpetriere hospital. Two eminent surgeons opened her chest to patch the shattered vein and massage her heart. At first, hopes among the waiting French and British dignitaries were high. But the haemorrhaging was too great; it led to a heart attack. At 4am, Diana, Princess of Wales died.