Video report by ITV News Correspondent Juliet Bremner
It reads like a movie-plot; A group of hardened criminals form a team to carry out the biggest heist of their careers before vanishing back into retirement.
But this story didn't pan out on the silver screen - it happened over the Easter Bank Holiday weekend in 2015 when a gang drilled into the vault at the Hatton Garden Safe Deposit company in Clerkenwell, London, and made off with £14m of loot.
The Hatton Garden heist was one of the biggest in English history and was carried out by career criminals from London's seamy underbelly - and the four ringleaders are linked to crimes stretching back decades, including two of the most notorious robberies of the 1980s.
Opening the case against the men in November 2015, prosecutor Philip Evans described Brian Reader, John Kenneth Collins, Terrence Perkins, and Daniel Jones as:
"Four ringleaders and organisers of this conspiracy, although senior in years, brought with them a great deal of experience in planning and executing sophisticated and serious acquisitive crime not dissimilar to this.”
Mr Evans told the jury that Reader and Perkins already had a place in English criminal history:
Three other men, Carl Wood, William Lincoln and Hugh Doyle have also been convicted for the raid.
Brian 'The Master' Reader, 76
The oldest member of the Hatton Garden mob, Reader was jailed for eight years in 1983 for his part in the £26 million gold bullion robbery from the Brinks-Mat security warehouse at Heathrow Airport.
On the day of the raid, the pensioner used his Oyster Freedom Pass to travel by public transport from his home in Dartford, Kent, to the scene of the crime.
However, the court had previously been told he withdrew from the heist after the gang failed to complete it in one night.
Terry 'Tel' Perkins, 67
Perkins had previously spent 22 years in jail for robbing the vaults of Securicor/Security Express in London in 1983 where £6 million in cash was taken during an elaborate raid.
He admitted conspiracy to burgle in connection with the Hatton Garden safety deposit raid.
Daniel Jones, 60
Jones has a string of convictions for theft, burglary and handling stolen goods from as far back as 1975.
When police searched his home, officers found jewelry and a "Forensics for Dummies" textbook.
He, along with mystery man "Basil", actually climbed through the hole that had been bored into the vault door.
Jones was described in court as one of the raid's ringleaders and an "extreme eccentric" who would apparently talk to his dog Rocket as if it were a human being and slept in a sleeping bag that once belonged to his mother. He pleaded guilty last year.
John Collins, 75
Pensioner Collins has criminal convictions dating back to 1961 that include robbery, theft, and handling stolen goods.
One of the gang - known only as "Basil" - who entered the Hatton Garden premises via the front door and let in the rest via the fire escape, has never been identified and remains at large.
It is also thought "Basil" was the gang member that crawled through the narrow hole into the vault.