Mark Gatiss uncovers supernatural storytelling, vampires and royal blood on Who Do You Think You Are?

"I jokingly said I want at least one murder and by the end I want to be King of Ireland. And in fact that’s exactly what happened," he tells

Mark Gatiss – known for his dark fantasy storytelling and roles in Game of Thrones, Wolf Hall and, of course, Sherlock – was “chuffed to bits” when Who Do You Think You Are? asked if they could delve into his family history. “I’ve been waiting for years!” he tells “I’d always hoped they might ask one day.”


The Doctor Who writer had a few ideas about where the show could go but “all the stuff in the programme was a total surprise” and much better than he ever imagined… 

“I jokingly said I want at least one murder and by the end I want to be King of Ireland. And in fact that’s exactly what happened,” he laughs. “At one point I actually said, ‘This is too good.’ It’s like everything I’m interested in in one package.”

Gatiss’s journey into his mother’s side and his Irish heritage uncovers murder, poison, poverty and the “marvellous” discovery that royal blood really does run in his veins.

His ancestors, the O’Kanes, were “descended from the high kings of Ireland,” he tells us. “It was thrilling. I had no idea. So obviously I’m going to form a small army and reclaim it…” 

It must be the dream of everyone who takes part in Who Do You Think You Are?, I ask. “Yes I know! As a confirmed republican, I don’t know what to do with myself!” he laughs. 

The star, who has always loved the ghastly and ghoulish, even comes into contact with vampires during the episode: “There’s a whole section on the supernatural and storytelling and vampirism to which one of my ancestors is directly linked. It’s amazing. You couldn’t make it up.”

Gatiss’s quest was “surprisingly startling.” He found himself moved by the small stories, he tells us, though not to tears. 

“I didn’t cry but I nearly did because the actual human story is very moving,” he says. “It’s an odd feeling. It’s not quite what I expected. I was always hoping to do it and that it would be fun and exciting, but it was surprisingly moving.”

“There were lots of odd little coincidences and also things that felt they were mixing into the pot to make me” – and one which has certainly left it’s mark: “I feel incredibly Irish now!”

In fact, Gatiss’s journey was so “hugely” inspiring that it could very well pop up next time he puts pen to paper, he admits.

“As a writer what I definitely responded to were these reversals of fortune and people’s lives being very up and down and sometimes quite desperate, sometimes quite prosperous. There’s a whole vampire story and the bulk of my family story is like an Irish Western, which is a brilliant subject. It’s about frontier life, it’s about people being transplanted from their own lands onto poor arable land and barely scraping a living. It’s about cattle rustling and revolution and anarchists. It’s amazing.” 

There was just one disappointment, and it came for his father Maurice. 

“He’s been lobbying for ages. He really wanted to look into our past – and then, of course, the episode has nothing to do with his side of the family…”

So now that filming has wrapped on WDYTYA?, Gatiss’s next challenge is to solve a mystery for his dad. 

“It’s a very unusual name Gatiss. We’ve never really got to the bottom of it. My dad’s dad said it was French… I don’t think it is. I think it’s a local corruption of gates or gatehouse or something like that. But it’s a curious name. I’d love to find that out.”


Mark Gatiss’ Who Do You Think You Are? is on Thursday 8th October at 9:00pm on BBC1