Two men who went on a £300,000 wrecking spree at a brewery in Blackburn which was illegally occupied by a group of 100 travellers, have been jailed.
Gang leader Thomas Ward, 43, and John Ward, 33, both of Aspull Common, Leigh, had earlier pleaded guilty to blackmail, conspiracy to burgle and conspiracy to commit criminal damage.
At Burnley Crown Court they were sentenced to four years three months and three years nine months.
Two others will be sentenced later.
The court heard the group cut a padlock at the yard entrance and threw the security guard out before demanding £20,000 to leave from the brewery.
The travellers caused an estimated £313,000 worth of damage to the premises when they realised they would not get paid.
Sentencing judge Andrew Woolman the damage brought an "unpleasant end" to 200 years of production at the site on Penny Street.
"It is clear that a considerable amount of wanton vandalism was carried out and some of the beer on the site had to be thrown out because of the risk of contamination," he added.
Among items stolen were four-and-half tonnes of copper cabling - along with televisions, computer equipment, cash, port, wine and spirits, the court heard.
Thwaites had been due to move to a new complex in Lancashire around 12 weeks after the incident, but was forced to terminate operations early.
The court heard the firm's chief executive Richard Bailey was "extremely stressed" and felt "powerless" at the time in the face of the increasingly aggressive behaviour by the travellers.
Patrick Ward, 32, who helped set up camp at the site in May, was convicted in his absence in November and remains at large.
Prosecutors said he was caught on CCTV stealing items from the town centre site.
A 17-year-old male, who cannot be named because of his age, also admitted the conspiracy offences and will be sentenced later by a youth court.