Game of Thrones star recalls Lannister detail in King & Conqueror as he compares shows

"Two allies with no design on the English throne," continues the synopsis, "who found themselves forced by circumstance and personal obsession into a war for possession of its crown."

Speaking to RadioTimes.com about potential comparisons between the two projects ahead of the show's release, Coster-Waldau said: "I’ve played at least eight or 10 cops in my life, so every time I play another police officer, I'm going, 'This is a police officer, I’ve done that before, but it's still very different, it's a completely different story.'

"And yes, this is set in a time where they sit on horseback and have swords, but it's a very different story."

But he did go on to acknowledge that the author of the Game of Thrones books, George RR Martin, was "very inspired by this time period".

"I do remember putting on my armour for the first time and noticing the sigils, which were exactly the same as the Lannisters' in Game of Thrones, the lions.

"So there are definitely similarities visually, but it's completely different."

As well as throwing himself back into stunt training for the role of William the Conqueror, Coster-Waldau and his co-star Norton also embraced a popular Icelandic custom to help ensure that they were in peak condition for the drama's more physical demands.

Read more:

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"Reykjavík [where they filmed] is tiny," said Norton. "More people live in York than the whole of Iceland, and they all love their swimming pools and their cold plunge and hot plunge," which Coster-Waldau had never done before – and it proved to be quite the surprise.

"The first time, you feel that you're about to die, and then you suddenly realise, oh, this is really nice," he added.

Norton also said that it made their training "really, really enjoyable, because we would always couple it with this custom, which is to get to soak in cold water and then basically poach in warm water".

"And so Nikolaj and I would always go down, do our stunts, and then head out... we had to be on it. We're not that young anymore."

King & Conqueror premieres on BBC iPlayer and BBC One on Sunday 24th August.

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