HBO has finally rubberstamped the first Game of Thrones spinoff, although it's not the one you might have been expecting.

House of the Dragon is being created by GoT author George RR Martin, along with co-showrunners Miguel Sapochnik and Ryan Condal.

Based on Martin's Fire & Blood and set 300 years before the events in Game of Thrones, the series will consist of 10 episodes and tell the story of the House of Targaryen.

Sapochnik, who directed the Battle of Bastards and The Long Night episodes - among others - will take the helm on the pilot and "additional episodes".

There is no date set for release yet.

There is also no word on why HBO cancelled the other, better known prequel series that was being developed by showrunner Jane Goldman (Kingsman: The Secret Service, Kick-Ass).

Starring Niaomi Watts, the untitled show reached the pilot stage but Deadline reports that Goldman has recently emailed cast and crew telling them the series is no more.

It was to be set thousands of years before Game of Thrones, feature the origin of the White Walkers and was originally green-lit in June 2018.

HBO has clearly switched its preference to the telling of a more recent backstory.