The Winter King Executive Producers Explain Major Changes To Bernard Cornwell's Books For Iain De Caestecker's King Arthur and More

Iain De Caestecker as Arthur in MGM+'s The Winter King
(Image credit: MGM+)

The Winter King debuted in the 2023 TV schedule as a fresh take on the story of King Arthur, based on the first of Bernard Cornwell's Warlord Chronicles novels of the same name. Starring Agents of S.H.I.E.L.D. alum Iain De Caestecker as the legendary Arthur Pendragon, the series is less than halfway through its first season, but readers already know that some very big changes have been made from the source material for the TV show. Executive producers Julie Gardner and Lachlan MacKinnon spoke with CinemaBlend to explain the challenges and the resulting changes for Arthur and others.

Of course, no adaptation of a book is going to be precise from page to screen. Both executive producers, who hail from the Bad Wolf production company, already have experience on TV adaptations of novels, with Julie Gardner working on His Dark Materials (which ended with an emotional finale in 2022) and Lachlan MacKinnon working on A Discovery of Witches. When I spoke with them about their new MGM+ series, I asked about the challenges in deciding what to cut and change in adaptations. MacKinnon responded, with minor spoilers for The Warlord Chronicles:

I think there always [are challenges] regardless of what the project is, because what works on the page so beautifully doesn't always work on the screen. One of the points... is in the novel itself, it's told from the point of view of Derfel. It’s his voice that we're discovering Arthur through, which I think is a huge strength in a way because it feels fresh because of that, because you're seeing Arthur through Derfel and also Nimue later on in the novel. So it's something that's really fresh. But there's two main challenges that that presents to us as the filmmakers, which is that when it's a series ultimately about King Arthur, you want to see King Arthur, and you don't want to wait for him until Episode 8.

Keeping Arthur – and therefore leading man Iain De Caestecker, who the EPs praised as a perfect fit for the role – off-screen might have been a tough sell for a show billed as The Winter King, and the future king's banishment by his father didn't mean the star remaining off-screen for half the season. MacKinnon continued, explaining the Arthur change and a notable one for Derfel (Stuart Campbell) compared to The Warlord Chronicles:

That was something that we felt really had to bring forward. Because, you know, whenever you speak to a broadcaster, everyone wants to know about Arthur. Then the other aspect was to do with the voiceover itself, because in some ways, by hearing the voiceover from Derfel, who's the old man, you know that he survived. And I think that takes a lot of the jeopardy away from, will he survive this moment? Or will he not?

Readers may know that Derfel is going to survive his harrowing situations if the show follows the major beats of the books, but The Winter King doesn't give viewers that reassurance, and the stakes remain high. As MacKinnon noted, what works wonderfully on the page just doesn't always translate to an ongoing series.

Executive producer Julie Gardner shared her thoughts on adapting the first book of Bernard Cornwell's saga to screen, noting the importance of the novels throughout the production process. She said: 

For our writers, Kate Brooke and Ed Whitmore, and Otto Bathurst, our lead director and EP, everyone would say Bernard's novels were the North Star, because they're brilliant. We love them, we go back to them all the time. But to Lachlan's point, sometimes you have to open things up or move things forward. But I think even when we've done that, we've based it on something from the novel.

Changing elements of the book doesn't mean tossing the book aside and going in wildly different directions, as the EP confirmed that the show's changes were based on the events of Bernard Cornwell's source material. She went on to address the most notable instance of a change from book to screen: 

The best example I can give is in bringing Arthur earlier in the series, compared to the novels. There was a line in Bernard's novels, which is something like, 'A ruler is frightened of their male bastards, but loves their female bastards.' And we knew we needed to do a backstory for Arthur to introduce him early in Episode 1. That whole banishment, that whole conflict with Uther came from that line of oh, he's a threat or he doesn't fit in.

His status as a bastard has been key to Arthur's characterization thus far, so it tracks for that particular line from the novels to inspire the changes early in the series. Viewers got to see Arthur earlier, and readers got to see how The Winter King could use content from one of the books in a different way. Julie Gardner continued: 

And then across the series, it became very clear. This is an undercurrent in the novels, it became very clear that being a bastard was a negative, but also a huge positive for Arthur because he sees the world differently, he thinks differently. He's got a greater independence, which makes him surprising in his kind of maneuvers. So yes, even when you're changing something, what you're trying to do is hold to the core of the novel, the spirit of the novel.

At the time of writing, The Winter King still has more than half a season to tell the story of the first novel. The executive producers also confirmed that they are thinking of a "five-season epic" adaptation of Bernard Cornwell's novels, so even readers may not know at what point Season 1 will actually end. 

You can find The Winter King via MGM+, which boasts original series in the U.S. on television, on-demand, online, and across devices. The adventure is only getting started with new episodes releasing on Sundays, so now is the time to catch up and tune in. If you're located in the U.K., you'll be able to find The Winter King streaming on ITVX before the end of the year.

Laura Hurley
Senior Content Producer

Laura turned a lifelong love of television into a valid reason to write and think about TV on a daily basis. She's not a doctor, lawyer, or detective, but watches a lot of them in primetime. CinemaBlend's resident expert and interviewer for One Chicago, the galaxy far, far away, and a variety of other primetime television. Will not time travel and can cite multiple TV shows to explain why. She does, however, want to believe that she can sneak references to The X-Files into daily conversation (and author bios).