Activist Mel Broughton dedicated his life to fighting for animal rights.
As a leading figure in campaign group Speak, he was determined to stop plans to build an animal research laboratory at Oxford University.
But in order to achieve his aims he waged a "fierce campaign" against people and institutions involved in planning the centre, jurors at the city's crown court were told.
They convicted the 48-year-old of conspiracy to commit arson, after hearing he was behind two petrol-bomb attacks on university buildings.
It was the second trial Broughton had faced over the allegations. A jury was discharged in November 2008 after failing to reach a verdict.
The improvised devices exploded at Queen's College sports pavilion in November 2006, causing damage put at £14,000.
Two similar bombs were planted underneath a portable building used as an office at Templeton College in February 2007 but failed to go off.
It was not the first time the activist, a single man from Northampton, had planned illegal violence in support of his cause.
Ten years ago he was convicted of conspiracy to cause an explosion likely to endanger life after police found a bomb in the boot of his car.
And he had previously received a six-month suspended sentence in 1988 for a failed plot to steal a dolphin from captivity in Morecambe, Lancashire, and return it to the sea.
DNA evidence was found on a Templeton College bomb
His attacks in 2006 were part of a concerted effort to stop the construction of the animal research centre in Oxford.
Prosecutor Neil Moore said Broughton had spent his life fighting for animal rights.
But his actions went further than lawful protests and he was said to be a key player in a violent and frightening campaign.
Companies, institutions and individuals perceived as being associated with the research centre were subjected to violence and intimidation.
Paul Harrison, of the Crown Prosecution Service (CPS), said: "While our society supports the right to free speech and to campaign peacefully, Mel Broughton went well beyond that by using force against a legitimate academic institution and business in an attempt to further his aims."
'Sense of paranoia'
Broughton told the court he had helped organise legal demonstrations against the lab and could understand why people chose to take direct action.
But he denied having anything to do with the bombs.
He said he had hidden the documents and equipment out of a sense of paranoia that police would "misinterpret" his ownership of them if found.
Broughton told the court he was constantly watched, filmed and followed by police.
A spokesman for Oxford University said: "The university has always accepted the rights of protesters to voice their objections within the law.
"However, we will continue to work with all relevant authorities to protect staff and students from criminal activity of any kind."