Actors at the York Dungeon got a masterclass in terror with “execution expert” and author Geoffrey Abbott.

Mr Abbott, a former Yeoman Guard – better known as a Beefeater – at the Tower of London, demonstrated beheading techniques to staff as they prepare for the museum’s latest exhibition.

Execution: Traitors Of York will transport visitors back to 1400s Micklegate Bar, where traitors’ severed heads were displayed as a warning to criminals.

Mr Abbott, 89, spent eight years as a beefeater after a 35-year career in the RAF, stationed in the Middle East during World War Two, and ended his career as a Warrant Officer with NATO, and gave tours to visitors to the Tower.

“Just about every first question of the tourists was ‘Where was Anne Boleyn beheaded?’ They didn’t want the history, they just wanted the bloodthirsty part”, he said. “People just love gruesome things – as long as they themselves aren’t being stretched on the rack.”

Since retiring, he has written more than two dozen books on the grisly side of British history.

Mr Abbott, who now lives in Kendal, is also an expert on execution techniques, and has worked on TV programmes including the BBC’s The Worst Jobs in History, with Tony Robinson. He also showed comedian Rory McGrath how to swing an executioner’s axe, for the Discovery Channel programme Bloody Britain.

“Of course, he did it very badly. I told him not to give up the day job,” Mr Abbott said. “I had him on the rack, and then on the thumbscrews.”

The new exhibition opens to visitors on Saturday.