Everything you need to know about the Game of Thrones prequel

We're so excited to watch the Westeros prequel!

Jon Snow and Daenery Targaryen haven't even defeated the White Walker threat yet, and already we're talking about the next project in the Game of Thrones universe – the first (as-of-yet untitled) spin-off show of the hugely popular fantasy series. The full cast has recently been announced, along with some key information about what time the series will be set and which of George RR Martin's many stories about the history of Westeros it might be based on. Find out everything you need to know…

What is it about?

We'd be surprised if there was any mention of the characters we know and love at all in the new series, as it takes place thousands of years before Robert Baratheon became king of the Seven Kingdoms. That's not to say that we won't get mentions of the Stark and Targaryens – who have been around for generations. The official synopsis reads: "Taking place thousands of years before the events of Game of Thrones, the series chronicles the world's descent from the golden Age of Heroes into its darkest hour. And only one thing is for sure: from the horrifying secrets of Westeros's 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."

Jamie will star in the prequel

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Who is starring?

Although we know almost nothing about their characters, it was recently revealed that Naomi Watts, Josh Whitehouse, Naomi Ackie, Denise Gough, Jamie Campbell Bower, Sheila Atim, Ivanno Jeremiah, Georgie Henley, Alex Sharp and Toby Regbo have all been cast in the new series. Naomi's character is described as "a charismatic socialite hiding a dark secret". Jamie was among the cast to speak about his new role, tweeting: "I'm shaking with joy to able to share this news with you. A real pinch me moment."

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When will it air?

Fans might have to wait a while for this one! HBO boss Casey Bloys revealed that the series won't be out until 2020 at the earliest, explaining: "If we do a pilot and series, nothing is going to air on HBO until at least a year after the final season. We're not doing a final season and then, 'Following it at 11 p.m.'"

READ: George RR Martin gives fans update on long-awaited Game of Thrones book

The prequel is set thousands of years beforeGame of Thrones

Who is behind the scenes?

Kingsmen: The Secret Service writer Jane Goldman is on board to write, and revealed that her sense of humour with her love of gore would certainly feature in the new series. Chatting to Digital Spy about combining the pair, she said: "I don't know if I'm allowed to say, but I would say yeah! Those are things I love, and things I like to do. It would be remiss of me not to put them in. So yeah." The showrunners of the original show, David Benioff and D.B. Weiss, won't be involved in the project.