A gang of gypsies who carried out a string of breakins at stately homes, including Britain’s biggest domestic burglary, were jailed yesterday for up to 11 years each.

Five members of the notorious Johnson family, who once bragged that they would gladly steal from “sirs and ladies”, stole antiques worth tens of millions of pounds. Their biggest burglary, at a mansion owned by the property developer Harry Hyams, brought them a haul estimated by art experts to be worth £80 million.

They raided houses across five counties and victims included the advertising tycoon Paddy McNally and Sir Philip Wroughton, Lord-Lieutenant of Berkshire.

Police believe that the Johnsons, an extended clan of Irish gypsies who live in caravan parks across Gloucester-shire and Worcestershire, have been at the centre of a crimewave for at least 20 years.

The brothers Chad and Albi Johnson, their father, Ricky, their cousin Daniel O’Loughlin and Michael Nicholls, their sister Faye’s partner, spent months researching their targets, then staking out the properties to work out how best to evade security.

During the raid on Mr Hyams’s Ramsbury Manor near Marlborough, scaffolding poles were attached to the front of a four-wheel-drive vehicle, which was used to smash down the front door. The gang grabbed what they could, including a 17th-century Thomas Tompion clock worth about £1 million, before the police arrived.

About £12 million of property from the burglary was found in an underground bunker near Stratford-upon-Avon, but nothing else was recovered and the rest of the antiques are thought to have been sold to “fences” and spirited out of the country.

The men were convicted in January after a month-long trial at Reading Crown Court, but the case can be reported now only because another case involving O’Loughlin was pending. Yesterday he admitted stealing a cash dispenser containing £55,000.

All five were found guilty of conspiracy to commit burglary between April 8, 2005 and October 13, 2006. Chad Johnson, 33, and O’Loughlin, 32, were both jailed for eleven years, Nicholls, 29, for ten, Albi Johnson, 25, for nine and Ricky Johnson, 54, for eight years.

Judge Christopher Critchlow said: “This must be one of the most serious examples of conspiracy to burgle ever to come before the court, considering the amounts involved. Little of the property has been recovered and is no doubt well hidden in the countryside or passed on for disposal.”

All the men had criminal records. Chad Johnson was convicted last year of marrying an heiress 38 years his senior under false pretences and stealing her £250,000 inheritance.

In 2005, the BBC made a documentary about the family called Summer with the Johnsons, in which they spoke about their love of such pursuits as hare coursing and bare-knuckle boxing. They accused the police of harassing them for no good reason, even though Ricky Johnson admitted that he had done “an awful lot of robbing”.

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