Doctor Who's John Simm joins Game of Thrones prequel

The Doctor Who star, Marquis Rodriguez (Luke Cage), Poldark's Richard McCabe, John Heffernan (Collateral, Brexit: The Uncivil War) and Dixie Egerickx (Patrick Melrose) will join up with an already stacked cast featuring Naomi Watts, Denise Gough, Josh Whitehouse and Miranda Richardson.

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Sadly, HBO have not provided any further details about the series, or who the actors will be playing in it. The only concrete information we have thus far is that Watts will lead the series as a "socialite with a dark secret", and that it will take place thousands of years before the white walkers descended upon Westeros.

The prequel series "chronicles the world’s descent from the Golden Age of Heroes into its darkest hour," according to Deadline. "And only one thing is for sure: from the horrifying secrets of Westeros’ history to the true origin of the white walkers, the mysteries of the East to the Starks of legend — it’s not the story we think we know."

The series will be written by Jane Goldman (The Kingsman series, Kick-Ass) from a story conceived by herself and GoT author George RR Martin. Production is set to begin later this year with the Game of Thrones prequel set to debut in 2020. The original Game of Thrones will conclude with its eighth and final series, starting in the US on Sunday 14th April with a UK simulcast in the early hours of Monday 15th April.