Lord Justice Scott Baker told the six women and five men selected for the jury on Tuesday that they must decide whether the deaths were an accident or - as the father of her companion Dodi Fayed contends - a murder orchestrated by Prince Philip and carried out by Britain's secret services.
"You will be in the public eye as no inquest jury has ever been before," said Baker, who is acting as coroner. The inquest is planned to last no more than six months.
The jury was shown a newly released photograph Tuesday, taken minutes before the crash in a Paris tunnel, in which Diana's head is visible in the back seat of the Mercedes, framed by the face of her body guard on the left and the driver to her right.
The photograph was the first new image made public from the evening of the princess' death in years. Britain's Sky News reports the 11 jurors will see more new photos and video as the inquest continues - dubbed "scene setting" evidence.
As proceedings began Tuesday, fewer than a fourth of the seats reserved for the public were taken.
Opening a decade after the couple and their chauffeur died, the inquest had to wait for French authorities to complete their inquiries and court proceedings, then for the London's Metropolitan Police to complete their investigation.
The French authorities and the Metropolitan Police agree basically that chauffeur Henri Paul had too much to drink, the car was going too fast, and that the crash in the Pont d'Alma tunnel was an accident.
Fayed's father, Mohamed al Fayed, disagrees. "I believe my son and Princess Diana have been murdered by the royal family," he said outside court.
Paul died along with Diana, 36, and Fayed, 42; bodyguard Trevor Rees-Jones was the sole survivor.
In his opening statement to the jury, Baker recapped the couple's relationship, which developed after July 14, 1997, when Diana was staying in the French resort of St. Tropez as al Fayed's guest; Dodi Fayed arrived later in the day and his girlfriend, Kelly Fisher, joined him two days later.
All parties to the case agree that Diana and Dodi Fayed did not have a serious relationship before then.
Baker said a remark Diana made to journalists on July 14, that "you're going to get a big surprise," preceded Fayed's arrival, as did a photograph of her in a swimsuit, which some have said showed an early pregnancy.
The coroner showed the jury the bathing suit picture and told them this picture was taken before Dodi and Diana began their relationship, CBS News correspondent Sheila MacVicar reported.
Al Fayed has claimed that Diana was pregnant with Dodi Fayed's child when she died, and that the couple had planned to announce their engagement on Sept. 1.
Their relationship did develop rapidly and the couple spent time together - though not continuously - in Paris, in Nice and aboard a yacht in the next six weeks.
Baker told jurors that al Fayed and other people in contact with Dodi Fayed at the end of August believed an engagement was imminent; people in touch with Diana thought not.
Turning to the fatal drive from the Ritz hotel starting at 12:20 a.m. on Aug. 31, Baker said the jury would have to consider whether Paul was intoxicated, why he took a peculiar route toward Fayed's flat, why he lost control of the speeding car, and whether anyone could organize a murder in the circumstances.
The decision for Paul to meet the couple at the rear entrance of the hotel apparently was made at the last minute in the hope of eluding paparazzi clustered around the front entrance. Al Fayed has said he urged Dodi to stay at the Ritz, but that his son wanted to return to his flat to present an engagement ring to Diana.
Had Paul followed the route that most professional drivers would have taken, "then any conspiracy to do murder in the tunnel would have been certain to fail," Baker said.
In a witness statement, al Fayed claimed that Paul was a paid agent of British and French secret services, that he was paid the equivalent of $4,000 to orchestrate the arrangements for taking the couple out of the back entrance of the Ritz, and that a post-mortem that determined that Paul was drunk had been fabricated, Baker said.
He indicated that the jury will also consider allegations that French medics might have saved Diana had she been taken to a nearer hospital, or been taken directly to a hospital rather than being treated at the scene as is the policy in France.
Baker said an expert he commissioned concluded that it was unlikely that Diana, who died from a ruptured pulmonary artery, could have been saved, and that the hospital where she was taken was best equipped to deal with multiple injuries.
A coroner's inquest has no authority to blame any individual for a death. The jury's role is to determine who died, when and where, and - the crux of this inquest - how.