The five men were jailed for a total of 49 years for burglary
Five men, including four family members, have been jailed for up to 11 years each for raids on stately homes - including Britain's biggest burglary.
Police estimates put their total haul in excess of £30m but art experts say it could be at least three times that.
The four members of the Johnson family, from Gloucestershire, and a man who is the partner of a family member, operated across several counties.
The judge described a raid in Wiltshire as the UK's biggest private burglary.
Details of the case were only revealed on Wednesday after reporting restrictions were finally lifted.
Paul Reid, prosecuting, described the men as an "extensive and highly organised gang" who were "ruthless in their intention to acquire high-value property".
Richard "Chad" Johnson, 33, and Daniel O'Loughlin, 32, were both jailed for 11 years, Michael Nicholls, 29, was given 10 years, Albi Johnson, 25, was jailed for nine years and 54-year-old Ricky Johnson was given eight years.
Ricky Johnson is father of Richard and Albi and uncle of O'Loughlin, while Nicholls was the partner of his daughter.
CCTV of Johnson burglars
They were all found guilty of conspiracy to commit burglary between 8 April 2005 and 13 October 2006 following a month-long trial at Reading Crown Court.
Judge Christopher Critchlow described the case as "one of the most serious examples of conspiracy to burgle ever to come before the court".
Police say the gang, based at a travellers' caravan park in Evesham, Worcestershire, had been operating in the south of England for 20 years.
They would stake out targeted properties, sometimes for weeks.
Their raids would last just minutes, with the balaclava-clad gang escaping in stolen cars.
Cases of this gravity must attract heavy sentences because of the deliberate criminality, organisation and sophistication of their planning and the effect on the occupants
Judge Christopher Critchlow
The raid on Ramsbury Manor, the home of property tycoon Harry Hyams near Marlborough, Wiltshire, is thought to be the most valuable domestic burglary ever committed in Britain.
Mr Reid said: "The collection is described as priceless.
"There is a difficulty in putting a value on antiques and antiquities - some of them very precious and very rare - but it is tens of millions of pounds."
Two months after the raid police found about a third of the haul in an underground bunker in a field.
The gang's other victims included Formula One advertising tycoon Paddy McNally and Lord Lieutenant of Berkshire Sir Philip Wroughton.
Items worth £100,000 were stolen from Sir Philip's home in Chaddleworth, Berkshire, when it was raided twice in 12 months.
In the burglary of Stanton Harcourt Manor, a 14th Century home in Witney, Oxfordshire, Albi Johnson leapt from a first-floor window to escape when challenged and broke both his legs.
He told doctors treating him in hospital he had fallen off his brother's garage roof.
The gang targeted Ramsbury Manor, in Wiltshire
The gang also targeted shops, in one night netting about £140,000 worth of televisions, china and glassware from three Worcestershire stores.
Five police forces were involved in the investigation, codenamed Operation Haul.
Officers described the gang as "forensically aware", leaving little or no trace of themselves at the scenes of their crimes.
Sentencing the men, Judge Critchlow said: "Cases of this gravity must attract heavy sentences because of the deliberate criminality, organisation and sophistication of their planning and the effect on the occupants."
He added: "Little of the property has been recovered and is no doubt well hidden in the countryside or passed on for disposal.
"You have no respect for people's property or the law so I have no alternative but to impose severe sentences."
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