By Sean Coughlan
After the failed attempt to blow up Parliament in November 1605, Henry Garnet, a Jesuit priest, was hanged, drawn and quartered, and his parboiled head displayed on London Bridge.
This book sold in 2007 is claimed to be covered with Garnet's skin
A 17th Century book describing the execution of this "barbarous traitor" sold at auction last year, with the unique selling point that its cover was allegedly made from the executed man's skin. But was the subject of this text really guilty?
On the day when the UK marks the anniversary of its most famous attempted coup, a historian is asking some awkward questions about one of those executed for his role in the Gunpowder Plot.
Glyn Redworth has been researching the letters of a Spanish aristocrat who lived in London during the years surrounding the plot - and he says these reveal evidence Garnet was wrongly condemned.
What brought Garnet to the scaffold in St Paul's Churchyard in 1606 was the claim that he knew about the plot but had failed to alert the authorities.
Dr Redworth's findings have come from his book The She-Apostle, telling the story of Luisa de Carvajal, a Spanish woman who came to London in 1605, with the aim of supporting England's Catholics, who faced persecution under the Protestant King James.
Robert Catesby led plot to kill James I and leading nobles on 5 November 1605
It was conspiracy of disaffected Catholic gentry wanting to overthrow Protestant elite
Gunpowder was concealed in cellar below Houses of Parliament
Anonymous warning revealed plot
Her letters have some familiar complaints - the housing in London is over-priced and the locals get drunk and rowdy at the weekends.
This is also a London of religious intolerance, violence, plagues, public executions, torture and secret agents, plots and counter-terror.
The man who brought her to this dangerous place was Henry Garnet, and Dr Redworth says the timing of her arrival, in the months when the plotters were planning their attack, points away from the idea he was part of the conspiracy.
If he was desperate to avoid detection while planning to kill the king, he wouldn't have smuggled in a Spaniard who stood out like a sore thumb, says the University of Manchester historian.
"He wouldn't bring over this rare and exotic woman, who couldn't speak a word of English, who could so easily attract attention and lead people to the plot."
Luisa, familiar with the Catholic families in London and influenced by the opinions of Garnet, reveals in her letters a deep hostility to the plotters.
The historian believes that Luisa’s criticism of the "foolish and impudent" plotters was a direct reflection of Garnet's own views, and suggests that he was wrongly arrested as a sympathiser.
While Garnet was accused of secretly supporting the plotters, Luisa's letters show there was no appetite for terror in Garnet's private circle.
In front of a modern jury, he would have been seen not as a dangerous conspirator but a "naive bumbler", says Dr Redworth.
But there was no denying Garnet did know something. In the confession booth he had heard a second-hand account of plans for a rebellion – and he sought to dissuade radical Catholic gentry who might be involved.
Guy Fawkes caught in the act
But the jury at his trial were unconvinced. Why hadn't he passed on his suspicions to the authorities?
Dr Redworth says on a previous occasion Garnet had tipped off the government. But there were so many plots and rumours of plots swirling around, it was not unreasonable for Garnet to hesitate.
And there was a political need to prove he was at the centre of the plot and not just a bystander. "They couldn't give him the benefit of the doubt," he says.
The ring-leaders had died in a shoot-out; other conspirators, including Guy Fawkes, had been caught, tortured and executed.
What made Garnet different was his status as leader of the Jesuit priests secretly operating in England.
The Jesuits were associated with a threat from overseas - and by punishing a Jesuit, it made it easier for King James to avoid blaming all English Catholics. In propaganda terms, it turned an attempted English rebellion into a foreign-inspired plot.
"By getting rid of the chief Jesuit, it allowed him to draw a line under the Gunpowder Plot," says Dr Redworth.
Michael Lobban, professor of legal history at Queen Mary, University of London, says the prosecution was designed to present Garnet as the chief manipulator who "directed and commanded" the plotters.
This cautious, scholarly son of a Nottingham head teacher was cast as leader of the hot-headed gentry who stacked cellars full of explosives.
We have to accept that according to the law of the time, he was guilty of sedition and treason
David Herber of the Gunpowder Plot Society
It was a successful tactic, supported by circumstance rather than any formal evidence. "The kind of evidence allowed at this time to convict people of treason was often very loose,” says Professor Lobban.
The jury only took 15 minutes to find Garnet guilty.
This remains one of the most famous crimes in British history - 5/11 in today's parlance - and Professor Lobban says there is still value in such re-evaluations.
"The more we can uncover about what Garnett did or did not do, the better. After all, we might have more evidence one way or another than contemporary prosecutors or jurors."
Such doubts do not persuade the Gunpowder Plot Society, which studies events surrounding the failed attack.
"We have to accept that according to the law of the time, he was guilty of sedition and treason and punished in accordance with that law," says the society's spokesman David Herber.
He also believes that far from being innocent, Garnet was "well aware of what was transpiring and chose to do nothing".
There was one more verdict on Garnet. The crowd who gathered to see the execution underwent a change of heart, turning against the executioners.
In one version of events the crowd pulled on his legs when he was hanging to save him from being disembowelled and ripped apart while still alive.
Garnet, says Dr Redworth, was “extremely unlucky” to have gone down in history as a Gunpowder Plotter.