Game of Thrones' Nikolaj Coster-Waldau talks playing unlikely hero Jaime Lannister, battles with bears and bidding farewell to Westeros

Nikolaj Coster-Waldau didn’t have the most auspicious debut in the opening episode of the TV show that would come to rule the world. Certainly not as far as the Danish actor’s mother was concerned.

“Well, Nikolaj, that was interesting,” was the mild response of Hanne Søborg Coster, a librarian, after watching her son engage in on-screen doggy-style sex with his twin sister, then throw a kid out of a high window to stop him telling tales.

That was April 2011 and Game of Thrones had started with a bang. HBO’s blockbuster fantasy has barely let up over the ensuing seven seasons, 66 episodes and 62 hours of culture-shifting drama. For the man who plays royal knight Jaime Lannister, things got really difficult after what we might call his relative indiscretion: his character spent one series in a cage, then suffered a brutal amputation. Less than handy if you’re a knight and that’s your sword hand.

Not that Coster-Waldau’s mother, or his wife, were any the wiser. “My mother hasn’t watched it since,” he remarks in impeccable, barely-accented English. “It wasn’t really up my mother’s alley, so to speak.”

It’s a “family thing”, reckons the ridiculously well-preserved 48-year-old when I meet him in The Corinthia hotel in Charing Cross. His younger daughter, 15, at home in a university town just north of Copenhagen, still hasn’t seen anything of the record-breaking show that began its final season earlier today at 2am (it’s on again this evening at 9pm). His older daughter, 18, reluctantly joined the 31 million viewers per episode in 170 countries, only because her friends were watching “so she thought she better check it out. But my wife’s only seen the pilot.

“To be fair, it’s always weird if you know someone really, really well, to see them pretend to be, in this case, a one-handed knight in a romantic sexual relationship with his sister. Half the time you look like someone on his way to a Halloween party,” Coster-Waldau notes with a cheerful self-deprecation. “So there is a ridiculousness to it, and the suspension of disbelief is difficult when you know someone really well. And if that’s how I feel, how must it be for my wife?” he laughs.

For anyone newly arrived on planet Earth, after seven series of gathering doom, winter has come: here be dragons and here be, finally, the climax of Game of Thrones.

The curtain-closing six episodes are set to involve multiple epic battles. The protagonists are the warring families: Jaime’s House Lannister versus the northern Starks (led by Kit Harington’s Jon Snow) and the dragon-toting Targaryens (led by Emilia Clarke’s Daenerys). Also making a play for the Iron Throne and ultimate victory are the ice zombies of the Army of the Dead led by the fearsome Night King — “Apocalypse Jack Frost”, if you like.

The global anticipation, then, is enormous, and so were the lengths to which producers on the show’s Belfast production base went to keep plot details secret.

Coster-Waldau says he’s heard the rumours of “multiple endings” having been shot, to throw any spoiler-hunters off the scent. It might be true, he shrugs, it might not. He wouldn’t put anything past the bosses in charge of HBO’s critical and commercial juggernaut.

“We got the scripts on iPad things — we don’t have the paper scripts any more, which is really annoying. You had to download this app called Scenechronize. But the scripts would then expire once the last scene had been shot. They would disappear, lost in cyberspace, I guess. It was ridiculous.”

Game of Thrones has been a game-changing saga both on and off-screen. Coster-Waldau’s character has become something of a hero, despite that tricky incest thing. He’s forged brilliant onscreen partnerships with a ribald knight played by Jerome Flynn (as in actors-turned-crooners Robson and Jerome), and with a noble warrior played by Gwendoline Christie (as in the Star Wars star, fashion muse and all-round ledge). Pushed to nominate a favourite scene, the Dane recalls the time he and Christie had to fight a bear.

“We shot most of it in Belfast, with a guy wearing a CGI blue suit. Then we also had to go to a place outside Los Angeles to shoot with Bart the Bear. That was a crazy experience, because it was a real bear who is a real diva. There was a set, with an electrical fence to protect the crew. Then the trailer opened and everybody had to applaud and cheer Bart! And slowly this bear came out… And then had to have whipped cream.”

Coster-Waldau had been famous at home since the age of 23 after starring in successful Danish thriller Nattevagten (Nightwatch). But GoT rocketed him internationally, as it did the rest of the cast, most of whom were unknowns at the outset.

Their earnings have risen accordingly. And for all the other inequalities in the brutal fictional kingdom of Westeros, at least there’s no gender pay gap. The core cast — Coster-Waldau, Harington, Clarke, Lena Headey (Jaime’s sister Cersei), Peter Dinklage (their brother Tyrion) — collectively bargained for wages both fair and lucrative: $500,000 per episode, rising to a reported $700,000 per episode for the final series.

As Clarke said in a recent Vanity Fair cover story: “I get f****** paid the same as my guy friends. We made sure of that.”

”Yes, we did it together,” affirms Coster-Waldau, ”all that negotiation stuff. So it’s not an issue. And it shouldn’t be, of course.”

On screen, naturally, things remain deliciously murky. Game of Thrones’s entangled endgame makes Brexit Hell look like a round of hide and seek. Coster-Waldau is familiar with the analogies — which family is going to leave with no deal? Or indeed, no heads?

Equally, he points out: “That’s the difference between Game of Thrones and Brexit: nobody really cares about the protagonists.” He smiles. “There’s just pure disgust at the politicians in England from everywhere, including from England. In Game of Thrones, even if you hate someone you still want to see what happens next.”

Naturally, being a liberal, right-minded northern European who’s spent much of the past decade working in Northern Ireland, he considers the whole thing a shame as well as a shambles.

“Look at London — it’s been the capital of Europe for many years. I was in London last Christmas and it was so packed with people from all over Europe, because that’s what you do. This is our city. So it’s just gonna be weird and sad when that is no longer the case.”

Next up for the actor is the Toronto shoot of thriller The Silencing. Then, after a family holiday, he’s headed to Los Angeles to play Macbeth at the Geffen Playhouse, “just to scare myself”.

But before all that, there’s that final, brutal dash for the Iron Throne. Did Game of Thrones end how he expected it to end? “Not quite,” Coster-Waldau replies coyly. “But it’s great. There is a logic to what the writers do, so it feels very true to the nature of this show. Surprises, yes, still. But it makes sense. It’s like when you read a great, great book. It’s so much fun — but then when it’s over, it kinda sucks.”

And when, at last, that closing episode ends on May 19 and we see Jaime Lannister on the throne/in his grave/down the pub, will Nikolaj Coster-Waldau experience something like a post-coital slump?

“Ha, I don’t know!” he laughs again. “But call me then and ask if I need any kind of assistance. It might very well be. Or there might just be this huge sigh of relief: it’s over.”

Game of Thrones is on tonight at 9pm on Sky Atlantic and NOW TV