Paul Duncan McGarrity apologies for being a bit rusty. Not just because it’s been a full month since he last performed this castle-based show at the Edinburgh Fringe, but because he’s wearing actual chain mail, which is starting to corrode.

That cumbersome outfit is just the start of what McGarrity does to indulge his passion. For this hour is a nerdy show, but in the best way. The comedian  throws himself fully into his interest in medieval history, and is keen to include others, not exclude them by showing off arcane knowledge. 

He does let slip just a few technical terms to reassure us he does know what he’s talking about, but David Starkey can probably rest easy as this treatment of the topic is decidedly tongue-in-cheek. After all, you’d probably not get the doyen of history documentaries saying of his inanimate subjects: ‘It’s time to take these pricks down a peg or two…’

One of three stand-up archaeologists in Britain – showing just how ubiquitous comedy is becoming as a sideline – McGarrity revels in his geekiness, perhaps over-emphasising how much this material wouldn’t go down to well in a rowdy weekend comedy club. With segments that start ‘my favourite regional body that administers castles…’ he portrays himself as someone more likely to storm a rampart than a stag party.

But that’s to downplay the charisma and confidence he brings to his delivery, orating with a stirring enough rhetoric to lead us into battle when he’s recreating the sort of historic scenes a castle might play witness to. Think period dramas starring Sean Bean.

The content is an easy mix of loosely related topics, a few historical nuggets mixed with gags abut how symbols of fearsome feudal power have become twee heritage destinations, complete with tea rooms and gift shops. 

Then there’s the stories about his castle-related hobby of medieval combat. Not battle reenactments, he’s keep to point out, but essentially a martial art with metal weapons and suits of armour. Like so much of the show, the material is carried by his enthusiasm, and a cheery retelling (with X-rays) of the eye-watering injuries he’s sustained at the wrong end of a sword.

Despite his protestations, tales of painful mishaps are pretty much mainstream stand-up territory, as are comic complaints about the likes of Tough Mudder participants and work colleagues demanding sponsorship for indulgent activities.

The central premise that he will attack a castle – literally, not just dissing them with his sick burns – pays out slightly disappointingly, but again McGarrity injects the telling with such life that no one really minds.

Surely this is one of the best stand-up comedy shows about castles out there…