Others, of course, remain soaking up the sun and sipping sangria. But Knight had a background that guaranteed him an enduring interest from Britain's more lurid tabloids: a history of involvement with Soho strip joints, links with East End villains of the Sixties, and husband of 23 years to Barbara "Babs" Windsor, original Cockney and Carry On actress.
It was a role he played to the hilt, right to the end when he returned to England, Luton airport no less, and into the welcoming arms of the law. Not just any old copper, though, Detective Chief Inspector Reid McGeorge, of Scotland Yard's Flying Squad, and all courtesy of the Sun newspaper.
The newspaper, with Sky Television, had paid a sum reputed to be about £50,000 for the privilege of taking a few final snaps of Mr Knight and his third wife, Sue Haylock, sipping champagne at their villa at Benalmadena, on the Costa del Sol.
Across five pages of the newspaper readers were treated to pictures of "Ron" looking "tanned and relaxed". He was coming back to "clear his name" and see his mum, Nellie, 87, who was ill with Parkinson's disease.
Fellow villains in Spain saw it differently. They saw a man whose businesses - an Indian restaurant called Mumtaz and a nightclub, RKnights - were in financial difficulties, and who feared for his safety at the hands of a new breed of criminals who had moved into the area. Another of Spain's long-term residents, the Great Train Robber, Charlie Wilson, had been shot dead in 1990. And for reasons no one has quite been able to explain, Knight had been beaten up at his nightclub and put in hospital two years ago.
The club had also been the scene of stabbings, shootings and punch-ups and the police were said to be about close it down.
If true, then these were changed days for the man who grew up in the East End, leaving school at 14 to work as a £2.50-a-week upholsterer and then as a rag-and-bone man, before graduating to Soho strip joints and peep shows.
Eventually he became a Soho club owner, emerging from decent obscurity in1980 when he stood trial for the murder of "Italian Tony" Zomparelli who had stabbed to death Knight's younger brother, David, in a nightclub.
Zomparelli was shot dead in Soho on his release, but Knight, who was said to have paid for the killing, was acquitted after his wife, Miss Windsor, gave evidence in court. It was to be a further 13 years before he appeared in the dock again charged with the theft of £5.9m and handling some of the proceeds from the Security Express robbery.
Despite meticulous planning police, investigating another matter, had almost stumbled on the scheme when officers visited a scrapyard owned by Knight's brother, James, and were led to a locked room where many of those later convicted for their involvement were holding a meeting.
"A number of men were sitting in a semi-circle and they seemed embarrassed by the police presence," Michael Worsley, QC, told the court yesterday. "There were no papers, but it looked like a business meeting. There were not jollity or drinks. The infere n ce was that this was a planning meeting."
However, a month later a gang of nine armed and masked raiders hit the company's headquarters at 10.30am over the holidays when just one security guard, who was told "co-operate or die", was on duty.
As his colleagues arrived, one 61-year-old guard, James Alcock, was doused in petrol and a box of matches rattled by his ear with the threat that he would be "incinerated" if he failed to hand over the keys.
For more than five hours the gang remained on the premises, eventually wheeling out on trolleys bundles of bank notes in denominations of £50 downwards totalling £5, 961,097.
For their part in the robbery, Knight's brothers, James and John, were sentenced to eight and 22 years imprisonment respectively. Terence Perkins also got 22 years for robbery, while John Horsley and William Hickson were given terms of eight and six years for handling the proceeds.
That left the Famous Five, including Knight, sheltering from British justice on the Costa del Sol. Freddie Foreman, a former associated of the Krays, was returned and jailed for nine years in 1990. With Knight out of circulation only three, Ronald Everett, Clifford Saxe and John Mason, remain.
The trio were among the guests at Knight's wedding to his third wife, Sue Haylock, at Fuengirola in 1987. It seems they could not resist cocking a snook at the law with the cake in the shape of a prison, not unlike the one where Knight last night began his sentence.