Deadline reports an untitled Game of Thrones prequel series from writer Jane Goldman (Kingsman: The Secret Service, Stardust) and A Song of Ice and Fire author George R.R. Martin has been given a pilot order at HBO, clearing the path for another series set in Westeros sometime after Game of Thrones takes its final bow with its upcoming eighth season.
The series will reportedly be set "thousands of years" before Game of Thrones, at the crucial moment in Westeros history known as the Age of Heroes (a period full of such great deeds that some Westerosi dismiss them as fairy tales), when many of the great houses of the kingdom were established, descends into "its darkest hour."
This is presumably a reference to The Long Night, the most brutal and terrifying winter in the history of Westeros. It lasted for a generation, devastated a continent, and perhaps most importantly, gave rise to the creatures known as The White Walkers. It's a formative period in the history of Martin's world, and given how important the White Walkers are to Game of Thrones' final seasons in particular, it could make the perfect prequel follow-up.
Goldman will script and showrun the pilot, based on a story crafted with Martin. Goldman and Martin will also executive produce alongside Game of Thrones executive producer Vince Gerardis and Damages co-creator Daniel Zelman.
It's not clear at this point what might happen to the four other prequel projects HBO has in development, if indeed anything happens with them at all. According to Deadline, at least one other prequel has a chance of a pilot order right now, though HBO is feeling no rush at the moment.
So, based on this news, we could know what the next Game of Thrones series will be (if this pilot goes to series) some time around the finale of the main series. It's been obvious for a while that HBO doesn't want to let go of its most popular property, and with Game of Thrones' ending on the horizon as Season 8 is in production, the network is getting more and more serious about what's next.