The Kray twins were kings of post-war London’s underworld for more than a decade – from the austerity of the 1950s through to the swinging 60s.

Until both were sentenced to life in 1969, Ronnie and Reggie were the most powerful and feared criminals the city had seen with connections in the British establishment that went all the way to the heart of government.

They also mixed with Hollywood superstars such as Judy Garland, Frank Sinatra, George Raft, Jayne Mansfield, and Robert Ryan, as well as influential politicians of the day, like Tory peer Lord Boothby and Labour MP Tom Driberg.

At the height of their powers, they were making the modern equivalent of £10 million every year through organised crime.

Though both are long dead there is still an enduring fascination with the Kray twins.

Over the years they have been portrayed on the screen by Spandau Ballet brothers Martin and Gary Kemp and more recently by Tom Hardy who played both brothers in the movie Legend.

What is less well known is the key role that various Glasgow criminals played in their rise to power – both as enforcers and advisors.

The twins often turned to the city’s hardmen to carry out hits on rivals or those who had crossed them or failed to pay debts.

The twins knew that those sent down to the Big Smoke from Glasgow were more violent and ruthless than anyone they could recruit locally in the capital.

In other cases, they would use their Glasgow connections to supply them with weapons and even explosives to target their enemies.

Author Colin Fry has written several books about the Krays.

He says Ronnie and Reggie and older brother Charlie would often ask Glasgow hoods to carry out acts of violence on their behalf in London – including contract killings.

In an interview in 2001, he said that the brothers had absolute trust in the Glasgow side of their operation.

Fry added: “The Krays were regularly in contact with people from Glasgow and they used about five or six local gangsters to do killings for them.

“They both had respect for the gangland bosses in the city.

“When they wanted a good hitman they would go to Glasgow.”

The Glasgow connection is said to have come through a rich American banker, who put the Krays in touch with the city’s main criminals around 1963.

Cooper had strong links with the Mafia and had been working for the infamous American godfather, Angelo Bruno when he met the Krays.

The American hit it off with them straight away and introduced them to his contacts in Glasgow.

It was to be the beginning of a Scottish connection that would never let the brothers down.

One police officer from the time said: “The men enlisted north of the Border were quiet, discreet and loyal.

“They did their jobs with a chilling professionalism.

“They went south, worked and then left. They were never a problem to the Krays.”

One of the Krays’ biggest allies was Glasgow crime godfather Arthur Thompson Senior.

Glasgow Times: Arthur ThompsonArthur Thompson (Image: Newsquest)

On one occasion he was said to have travelled by train from Glasgow to London and taken a taxi to their infamous Double R club where they regularly hung out and threatened them with a sawn-off shotgun which he had been carrying in an overcoat.

He is then reputed to have said: “My name is Arthur Thompson from Glasgow and you’ll no forget me.”

Holding the gun at the twins until he backed off to the door of the club, Thompson turned and walked swiftly to a waiting cab before heading back to Glasgow.

It is not clear to this day what prompted this confrontation.

Despite this “misunderstanding” Thompson became close allies of the notorious London gangsters.

It’s rumoured Thompson was present when Ronnie infamously shot George Cornell of the rival Richardson gang in London’s Blind Beggar pub in 1966.

Thompson would also arrange “hits” for the Krays in London – and they would do the same in return in Glasgow.

He was friendly with another legendary London gangster and Krays associate – “Mad” Frankie Fraser.

Fraser, now dead, once recalled: “Down south, we viewed Glasgow as the Wild West. The violence was on a much, much higher level.

“So the person in charge would have to have been something very special, and Arthur was certainly that.”

It was also rumoured that Thompson and the Krays were involved in the 1963 Great Train robbery when £2.6m (equivalent to around £30m now) was stolen from the Glasgow to London mail train.

During his trips to London Thompson had become friends with one of the ring leaders, Buster Edwards, who would later attend the funeral of Arthur’s murdered son, Arthur Jnr in 1991.

When fellow gang member Ronnie Biggs was asked shortly before his death in 2013 if Arthur was involved in the robbery, Biggs replied cryptically: “I might be dying but I’m not a grass.”

Reformed criminal turned artist and sculptor Jimmy Boyle was also said to have connections to the Krays before his conviction in 1967 for the murder of criminal William “Babs” Rooney in Glasgow

Such was Arthur’s influence the Krays would often turn to him for advice.

In a meeting in Glasgow – in the mid-1960s – they told him of a plan to take over the Beatles from their manager Billy Epstein.

The meeting between the three feared crime bosses took place in the now-demolished Cockatoo Bar on Pollokshaws Road in Govanhill.

It is believed they had been planning to “force” the pop guru into handing over his business.

But the twins were talked out of their takeover plan by Thompson.

He warned them off and pointed out that if they were linked to The Beatles it would destroy the band’s career.

Another Kray ally was Pat Connolly originally from Maryhill in Glasgow.

Glasgow Times: Pat ConnollyPat Connolly (Image: Newsquest)

The powerfully built hardman was their minder and also did security work.

He moved down to England in the 1950s and spent time in Brixton Prison where he first came into contact with the twins.

After his release, he began working for the Krays at the Double R Club as a part-time doorman and barman.

Connolly’s weighed between 17 and 18 stone and was physically intimidating and as hard as nails.

After the twins were arrested in 1968, he was said to have moved back to Maryhill, Glasgow where he married and had a family He passed away in 1996 in the city.

The Krays’ final arrest in 1968 even had a Glasgow connection.

They had sent a courier, Paul Elvey, to the city to collect dynamite.

But on his way back to London he was arrested and his evidence was used against the Twins by police at their trial in 1969.

Another Glasgow connection to the Krays was notorious armed robber James Crosbie.

He was jailed in 1954 for four years and worked in the print shop in Verne Prison in Dorset.

Crosbie later recalled: “A fellow con asks one day if I’d do a job for the ‘twins’. He was talking about Reg and Ron Kray.”

The notorious gangsters wanted fake driving licences and they were willing to pay big money. Crosbie agreed to do it for £500 but claims he never saw a penny.

The Scottish connection was not just confined to Glasgow.

John Dickson and Ian Barrie, who were both from Edinburgh, had key roles in their London organisation known as ‘The Firm’.

As recently as 2012, a collection of 215 letters by Reggie Kray was auctioned in Glasgow by McTears.

The exchanges were written while he served a life sentence in prison to Carol Clerk, the ghostwriter of his autobiography.

The letters were valued at between £10,000 and £15,000.

At the time McTear’s described them as being “historically important”.

The Krays were sentenced to life imprisonment in 1969 for their involvement in armed robberies, arson, protection rackets, assaults, and the murders of rivals Jack ‘The Hat’ McVitie and George Cornell.

Reggie had repeatedly stabbed McVittie in the face and neck for not following orders.

Ronnie had shot Cornell between the eyes in the Blind Beggar pub in the East End of London.

Ronnie died in 1995 from a heart attack while being detained in Broadmoor Hospital.

Reggie died from cancer in October 2000, eight weeks after he was released from his term on compassionate grounds.

Their long-time ally Arthur Thompson however had passed away in 1993 after suffering a heart attack in his home.