Game of Thrones creator George R. R. Martin has revealed that the Stark family will play a key role in showrunner Jane Goldman's upcoming spin-off series.
He also teased that, while fan concerns about the absence of dragons in the show are true, "direwolves and mammoths" will appear.
A pilot for the series, which is set 5,000 years before the events of the original show, is currently filming in Northern Ireland.
Martin told Entertainment Weekly that the series will feature a more fragmented version of Westeros, with roughly 100 kingdoms in place rather than the seven, clearly defined kingdoms in place at the beginning of Game of Thrones.
He said: "The Starks will definitely be there.
"Obviously the White Walkers are here — or as they’re called in my books, The Others — and that will be an aspect of it.
"There are things like direwolves and mammoths.”
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The 70-year-old author also revealed that the Lannister family will not be in existence in the spin-off, but that their ancestral home of Casterly Rock will be held by its namesake family - the Casterly clan.
Martin also teased that the name of the show might change, as his previous suggestion The Long Night was used for the title of the third episode of the eighth and final season, which featured the Battle of Winterfell.
The working title Bloodmoon is being used during filming.
Martin said: “I heard a suggestion that it could be called The Longest Night, which is a variant I wouldn’t mind. That would be pretty good.”
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The Westeros creator suggested that, like Game of Thrones, the latest HBO series will have a "large ensemble cast", rather than promoting any specific star as the lead.
Naomi Watts, Naomi Ackie, Denise Gough, Miranda Richardson and Jamie Campbell Bower have already been announced as part of that impressive ensemble.
Goldman's project is just one of a number of Game of Thrones spin-off products currently in the pipeline at HBO, with fan theories already running wild.
Martin is still working on The Winds of Winter, which will be the sixth and penultimate entry in his A Song of Ice and Fire series of books, which were adapted for the show.
Final entry A Dream of Spring is expected afterwards, though Martin has made it clear he will not start on that climactic tome until its predecessor is complete.