Juvenile success as amateur boxers and National Service in the Army did little to instil discipline or control the violence which was to become a hallmark of their lives.
Together with his late brother Ronnie, the twins' stylish image, reinforced by a series of portraits by the photographer David Bailey, captured the imagination of Cockneys, film stars, even peers of the realm.
But the reality was shocking, characterised by protection rackets, extraordinarily grotesque violence and murder.
Following the twins' convictions for murder in 1969, Reggie Kray became one of Britain's longest-serving prisoners.
In August, Home Secretary Jack Straw ordered his release after he was diagnosed with terminal cancer and given just weeks to live.
Violent lives
Reggie and his brother Ronnie were identical twins, born in 1933 and raised in the East End of London.
Juvenile success as amateur boxers and National Service in the Army did little to instil discipline or control the violence which was to become a hallmark of their lives.
Back in the East End in the 1950s they set up a protection racket, collecting money by threats from shopkeepers, and in 1960 moved into the West End to open a gambling club, Esmerelda's Barn, in Knightsbridge.
Even so, the Krays were virtually unknown to the general public until 1964, when the Sunday Mirror newspaper ran a story that Scotland Yard had been investigating a homosexual relationship between a prominent peer and a leading thug in the London underworld.
Although no names were mentioned, it soon became clear that they were Ronnie Kray and Lord 'Bob' Boothby, a media personality and former Conservative minister.
Boothby denied any impropriety but it later became clear that he was closer to the Krays than he had claimed.
At the time the newspaper backed down, sacked its editor, apologised, and paid Boothby £40,000 in an out-of-court settlement.
Reign of terror
Over the next four years, the Krays imposed a reign of violence in the London underworld, before being arrested for murdering two other gangsters.
Ronnie, a psychopath, had shot George Cornell in the Blind Beggar public house in Whitechapel in 1966 for calling him a "fat poof".
A year later Reggie stabbed Jack "The Hat" McVitie in a flat in North London.
Scotland Yard had been on the trail of the Krays for years, and in 1968 they were arrested by Detective Superintendent "Nipper" Read and charged with murder.
They appeared at the Old Bailey in 1969, along with members of their gang, including elder brother Charlie, who got seven years for other crimes.
His brothers were jailed for life with a recommendation that they serve 30 years.
Their incarceration did little to suppress the Kray legend.
Reggie claimed to have become a born-again Christian.
He had married in 1965, though his wife later committed suicide.
In 1997 he married Roberta Jones, an English graduate.
Campaign for release
Over the years a campaign for the twins' release built up.
Their supporters claimed that they were guilty only of crimes against other criminals.
In 1990 a full-length film, "The Krays", earned £255,000 for the twins and Charlie.
Reggie was devastated when Ronnie died in prison in 1995, and he was allowed out of prison to attend the vast East End funeral.
In 1998, Reggie's application for parole was refused.
The Parole Board said that he remained a devious and manipulative personality.
There was a suggestion that the boxer Mike Tyson might visit Reggie Kray during his trip to Britain in January but Tyson pulled out because he felt that any meeting would further tarnish his own image.
Charlie Kray died in prison in April this year while serving time for masterminding a £69m cocaine smuggling plot.
Though his health deteriorated in recent years, Reggie kept himself in the public eye, giving television and radio interviews.
"I believe that Ron and I were predestined to become known, either by fame or infamy", Reggie once wrote.
"I seem to have walked a double path most of my life. Perhaps an extra step in one of those directions might have seen me celebrated rather than notorious."