He’s the King of Crime thanks to a 30-year reign with Detective Inspector John Rebus. As Ian Rankin headlines the Theakston Old Peculier Crime Writing Festival this month, he speaks to ANN CHADWICK

AGATHA Christie’s ghost haunts the Old Swan Hotel in Harrogate, where the police found her after she mysteriously disappeared in 1926. Nowhere is the genre more enthusiastically celebrated than at the Theakston Old Peculier Crime Writing Festival, now in its 15th year. “This would be a wonderful setting for a murder,” PD James said as she surveyed the hotel grounds at the 2011 Festival.

It may look like a perfect Agatha setting but ‘the butler did it’ is far removed from the troubled, urban Edinburgh that Ian Rankin is known for.

“This upper-middle-class thing that Christie wrote about didn’t mean anything to me living in a coal mining village in Scotland,” Ian said. “She was an indefatigable plotter, I’m useless at working out her mysteries.”

Rankin’s latest, Rather Be the Devil, sees Rebus in his late sixties, not at best physical peak. Rankin, now 56, took a year off from the Rebus treadmill after experiencing a midlife crisis of sorts when his friend, the author Iain Banks, died in 2013.

“A lot of my friends were dying in their fifties and early sixties, and I thought dear God, maybe I should just take my foot off the pedal and try and enjoy life…It was lovely, and I sort of fell in love with writing again, I started writing tiny micro stories– not to show to anyone – just for the fun of doing it. It took me back to the early days when I was at school and at university, when you had a couple of spare hours and sat down and thought, ‘What am I going to write?’, and see what got channelled onto the paper.”

Rankin has sold more than 20 million books. His first novel had an advance of £200, but he’s been ranked as one of the most successful authors of all time, with an estate worth millions. He admits success is great: “You know, sitting here in my big house with a big car parked outside, it’s lovely. But at heart, you’re only as good as your next book and when I sit down to write my next book none of that success means anything … that fear that this time it will be a bad book, or this time there’ll be no book because you’ve dried up – that fear never leaves you no matter how much money you’ve got in the bank. And it’s why writers keep writing, it isn’t just about the financial success, it’s about using writing as therapy, writing as a pleasure, we keep doing it because it’s what we do.”

Every year, the Theakston Old Peculier Crime Writing Festival picks a novel for its Big Read. For 2017, their reader-in-residence, author Mari Hannah, will take Ian’s breakthrough book, Black and Blue – Rebus’s eighth outing – to libraries and reading groups. It was the book that marked Rankin’s commercial breakthrough, but one that’s bittersweet – he wrote it after his son Kit was diagnosed with Angelman Syndrome, a genetic disorder that causes severe physical and intellectual disability.

“Bittersweet is as good a description as any,” Ian says. “My son was being diagnosed with severe special needs, and I was asking big questions – why me, why us, what does this mean for us – but because I’m a novelist I was able to channel that into that book and it made it a big angry, questioning book. That’s partly the reason why it was such a success, so yes, bittersweet. But with the fame that eventually came, money came as well, which means we can look after Kit – anything he needs in way of equipment or special vehicles to take him around in his wheelchair we can get them because of the success of the Rebus novels. It’s all connected, everything’s connected, and Black and Blue was the first book I was happy with. All the books before it had been an apprenticeship, to learn about the genre and what you can and can’t do with it – and just become more confident about Rebus as a character.”

Many have drawn parallels with Ian’s life and his fictional creation. Both were born in Fife, lost their mothers at an early age, and have children with physical problems.

“Crime writing is fantastically therapeutic. If I walk out the house and someone nearly runs me over, I’ll just go into my office and type a scene out where they don’t make it to the next roundabout. That’s great, it’s very, very therapeutic and you can get rid of a lot of your demons that way. But also people come to crime fiction because they’re interested in the world, they’re interested in the mess we’re in, so if you want to tackle politics, if you want to tackle corruption, social issues, then the crime novel is a really good way of dealing with it because it asks the reader big questions about morality and the state of the world.”

Ian has a fondness for the Festival, not just because of the Festival.

“I’ve got family round that way. Whenever I’m in Yorkshire, I try catch up with family because my mum was born and brought up in Bradford, so I’ve got cousins and aunts and uncles in the neighbourhood.”

Edinburgh has built a tourism industry out of Rebus, maybe Bradford could be next?

“I’m half Yorkshire!”

How great it would be if his next book was set in Bradford?

“Wouldn’t it, yeah? Bradford needs more crime writers. And indeed Harrogate … what problems lurk below the surface?”

Ian Rankin is a Special Guest at the Theakston Old Peculier Crime Writing Festival, 20-23 July at The Old Swan Hotel, Harrogate, alongside Lee Child, Robson Green, James Runcie, Arne Dahl, Kathy Reichs, Dennis Lehane, Stuart MacBride and Peter May.

W: harrogateinternationalfestivals.com

Box Office: 01423 562 303.