Thieves struck the Hatton Garden Safe Deposit Ltd. over the four-day Easter holiday in April, gaining access through an elevator shaft before using a drill to bore through a 6-foot-thick wall and enter the basement vault, investigators said at the time.
Three of the accused -- William Lincoln, 60; John Harbinson, 42; and Carl Wood, 60 -- are charged with conspiracy to burgle.
Along with Hugh Doyle, 48, they are also charged with conspiracy to conceal, convert or transfer criminal property, while Doyle faces an additional charge of actually concealing, converting or transferring criminal property.
The men deny all the charges.
'Ringleaders' already pleaded guilty
On the opening day of the trial at Woolwich Crown Court, prosecutor Philip Evans told the jury that four other men -- John Collins, 74; Daniel Jones, 58; Terrence Perkins, 67; and Brian Reader, 76 -- had already pleaded guilty to conspiracy to burgle
in relation to the case.
The guilty pleas of those men, whom he described as "ringleaders and organizers" of the crime, was "evidence that there was in fact a conspiracy to burgle," he said.
The prosecution would attempt to persuade the jury of six men and six women that Lincoln, Harbinson and Wood were also party to the conspiracy, he said.
"These four ringleaders and organizers, 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," he said.
"Two of these men had also been involved in some of the biggest acquisitive crimes of the last century, and the other two had for many years in their earlier lives been involved in serious theft."
Their level of experience, and the magnitude of the crime
, meant that they would only have involved others "who could be fully trusted," he said.
YouTube tutorials; 'Forensics for Dummies'
Evans told the court that the burglary had been planned for almost three years, with the group meeting regularly before and after the crime in a pub in the London borough of Islington.
As far back as August 2012, one of the men involved in the crime had searched on the Internet for drills, and by May 2014 the searches had progressed to YouTube tutorials on how to use a specific drill.
A search of Jones' home had turned up a copy of a book called "Forensics for Dummies," Evans said.
He said police also searched the home of Reader, a figure referred to by his co-conspirators as "The Guv'nor" or "The Master," where they found a book on the diamond underworld, a diamond tester, a diamond gauge, diamond magazines and a distinctive scarf he was seen to be wearing at Hatton Garden in April.
During the heist, the thieves broke into 73 deposit boxes, 44 of which were being actively used, Evans said.
While media outlets had speculated that the value of the haul could be in the vicinity of £200 million ($303 million), currently estimates placed the value of the stolen property at £14 million, he said.
Evans also told the jury that burglars had been only "partially successful" in their attempts to break in to the vault on the first night of the heist, April 2. They returned two nights later, "with more new equipment to finish the job," he said.