On August 8, 1963, the men ambushed the Glasgow to Euston mail train as it passed through the Buckinghamshire countryside close to Cheddington and seized 2,631,684 in used notes.
The sum would be worth more than £40 million ($79 million) today.
Biggs was initially jailed for his part in the robbery but served just 15 months of a 30-year sentence before he escaped prison by scaling a 9m wall and escaping in a furniture van.
He went to Paris for 40,000 worth of plastic surgery before travelling to Australia and living with his wife Charmian and two children. After the authorities discovered him he fled to Brazil and was tracked down by an undercover reporter and later, Detective Inspector Jack Slipper of Scotland Yard.
However, police had difficulty bringing him back to England because Biggs had fathered a child with his Brazilian lover and lived in Rio for almost three decades. He was forced to return to Britain because he needed medical treatment and came back at the age of 71, on a private jet funded by the Sun newspaper.
Bruce Reynolds, who masterminded the heist, died in February this year, at 81, months before the 50th anniversary of the robbery.
Biggs was pictured at his funeral earlier this year, and appeared defiant. After his release from prison in 2009, Biggs said: "I am proud to have been one of them [train robbers]. I am equally happy to be described as the 'teaboy' or 'The Brain'."
He said he had few regrets about the heist, apart from people - including the train driver - being injured. Jack Mills was hit with an iron bar during the raid and never worked again.
"The people who paid the heaviest price for the Great Train Robbery are the families," said Biggs. "The families of everyone involved in the Great Train Robbery, and from both sides of the track.
"All have paid a price for our collective involvement in the robbery. A very heavy price, in the case of my family.
"For that, I do have my regrets."
Anthony Delano, who wrote a book about the heist, told Sky News that Biggs has exaggerated his role in the Great Train Robbery, which involved 16 men, and enjoyed the notoriety the story had gained him.
He said: "He was anything but a hero. People are beginning to realise his part in the actual robbery was very small. He was a smalltime south London crook who nobody really wanted on the team because he was likely to be a weak link."
