The Portland Tiara was stolen from the Welbeck Estate in 2018.
A six-strong gang stole a £3.75 million jewellery collection, including a tiara worn to the coronation of Edward VII, as part of a series of “ruthlessly executed” burglaries, a court heard.
Nottingham Crown Court heard the 2018 theft of the Portland Tiara and associated brooch from the Welbeck Estate in Worksop, was a “shocking event” and it will never again be seen in its original state.
Ashley Cumberpatch, his partner Kelly Duong, Kurtis Dilks, Matthew Johnson, Adrian Eddishaw and Andrew MacDonald are all accused of conspiracy to commit burglary in connection with the theft of the “national treasure”.
Prosecutor Michael Brady QC told jurors that property stolen during the burglaries and robberies was passed to professional handlers Tevfik Guccuk and Sercan Evsin, who were tasked with selling the items.
The Crown’s QC said: “Those responsible for this part of what was highly sophisticated criminal offending, Evsin and Guccuk, operated an ostensibly legitimate jewellery business in Hatton Garden.
“Such was the value and conspicuous nature of some of the items stolen that it was not possible to sell them in the UK.
“The inference to be drawn from the evidence is that at times the property had to be disposed of abroad.”
Addressing the theft of the tiara, Mr Brady said: "Stolen during the burglary were two pieces of diamond encrusted jewellery, the Portland Tiara and an associated brooch, with a combined value of approximately £3,750,000.
“The tiara and brooch formed part of the Portland Collection. It is difficult to overstate the importance and cultural value of these pieces of jewellery.
“Other works of art that formed part of the same collection included masterpieces by Michelangelo, van Dyck, Stubbs and a pearl earring worn by Charles I at his execution.
“These were trophy pieces of the gallery’s exhibition – extremely valuable, unique and of significant historical importance.
“They were displayed for the public’s enjoyment. Their theft is a shocking event and means that they will never again be seen in their original state.
“It is self-evident that burglaries of this nature require detailed and careful planning, including consideration of how to dispose of such unique pieces, an exercise that, to reduce the risk of detection to those who commit the burglary, is frequently undertaken as soon as possible after the property is stolen.
“As we will see, that is exactly what occurred here.”
The 6th Duke of Portland commissioned Cartier to create the Portland Tiara for his wife, Winifred, Duchess of Portland.
She wore the diamond-encrusted headpiece, whose centrepiece is the Portland Diamond, to the coronation of King Edward, the Queen’s great-grandfather, dans 1902.
Mr Brady continued: “Each was wearing an outfit designed to prevent identification and eliminate the risk of leaving any scientific evidence at the scene: motorcycle helmets, boiler suits, overalls and gloves.
“Each was carrying a hand or power tool, used to gain entry to the gallery, vault and display case.
“Their sole target was undoubtedly the Portland Tiara and brooch. The three burglars immediately made for them. They weren’t interested in anything else.
“On any view, this was a professionally executed, well-planned offence.”
Cumberpatch, Duong, Dilks, Johnson, Eddishaw, MacDonald, Evsin and Guccuk, alongside Darren Stokes, Gordon Thornhill, and Christopher Yorke, all deny involvement in the series of burglaries.
Le procès continue.