Tomorrow the nation marks 20 years since Princess Diana was killed in the crash that also claimed the lives of Dodi al Fayed and driver Henri Paul.

Her bodyguard Trevor Rees-Jones survived but suffered horrendous injuries to his brain and chest, including breaking every bone in his face.

The former paratrooper had been sitting in the passenger seat of the Mercedes S280 when driver Henri Paul hit a pillar in the Pont de l’Alma tunnel at speed in the early hours of August 31, 1997.

Both the driver and Diana’s boyfriend Dodi al Fayed were declared dead at the scene by emergency workers with Diana and Mr Rees-Jones taken to Pitie-Salpetriere Hospital, where the former Princess of Wales was later pronounced dead within hours.

Princess Diana’s bodyguard, now known as Trevor Rees, was saved by surgeons who used 150 pieces of titanium to rebuild his broken face, using family photos as a guide.

Due to his injuries he was sedated for nearly two weeks following the smash and suffered from amnesia for months afterwards.

While events of the night have been raked over time and again over the years, Mr Rees can actually remember very little of what happened.

Diana and Dodi had been staying at the Ritz hotel in Paris after a spending nine days on Dodi’s yacht in the Mediterranean but planned to move to his apartment close to the Champs-Elysées.

The plan was for the couple to leave by the hotel’s back door in an attempt to avoid the pack of paparazzi waiting outside.

Mr Rees told the 2008 inquest in London: “I wasn’t happy as it meant Dodi would be splitting the security officers, but I went along with it.

“Initially I had been told that Dodi and Diana would travel without security and I said this would not happen, that I would travel in the vehicle with them.”

The photographers quickly gave chase as they pursued the limo across the French capital with Mr Paul driving at around 65mph in an attempt to lose the media pack but the car hit a pillar in the underpass.

Expert witnesses told a Metropolitan Police investigation in the mid-2000s that Mr Rees had “very limited recall” of what happened immediately before and after the crash, adding this situation was unlikely to ever change.

Dr Maurice Lipsedge, a psychiatrist, said at the time: “Trevor Rees-Jones remembers getting into the Mercedes in the Rue Cambon and the car driving off, he remembers nothing after that.

“A few snatches might come back to him but his memories are not at all reliable because even for him it is impossible to tell if these are genuine memories or reconstructions of events from information he might have had later, dreams or imagination.”

However, Mr Rees’ claim of memory loss was challenged by Dodi’s father, Mohamed al Fayed, who claimed he “knew exactly what happened” before the Mercedes entered the tunnel amid allegations there were details the security services wanted to suppress.

Mr Rees eventually resigned from his job with Mr al Fayed in April 1988 on the advice of his his solicitors, with the bodyguard later claiming he had felt pressurised by the former owner of Harrods to remember what had happened.

In 2000, Mr Rees published his version of events in the book The Bodyguard’s Story: Diana, The Crash and the Sole Survivor, which reportedly earned him £1million.

Operation Paget, a police inquiry established in 2004 to look at the various conspiracy theories surrounding Diana’s death, found there was no evidence that Mr Rees-Jones remembered the crash nor that there was any evidence security services were involved in producing the book.

The investigation also dismissed claims Mr Rees-Jones had been given a job in United Nations security as “an inducement to ensure his continued silence”.

Born on March 3, 1968 in Rinteln, Germany, Mr Rees’ family had close connections with the army, where his father, Colin Rees, was a British Army surgeon and his wife Gill was a nurse.

When he was 10 his family moved to Oswestry in Shropshire and attended Fitzalan School, where he met his future wife Sue Jones.

At school he was a member of the Combined Cadet Force and after taking his A-levels he joined the 1st Battalion Parachute Regiment, going on to serve in Northern Ireland.

Leaving the army he went on to work for Mohamed al Fayed as a private security guard.