Game of Thrones spin-off series an 'embarrassment of riches' for HBO

In two years' time, Game of Thrones will end its incredible eight-season run and conclude the fantasy epic... for a while, anyway. Network HBO is ensuring the story will continue with a number of new series that expand the world of George RR Martin's celebrated books.

HBO has five different spin-off shows in the various stages of pre-production right now, each of them set to star entirely new casts of characters and being worked on by some top writers including Jane Goldman (Kingsman: The Secret Service) and Carly Wray (Mad Men, Mindhunter).

Other series are being developed by Max Borenstein (Kong: Skull Island) and Brian Helgeland (LA Confidential, Man on Fire), along with others.

HBO are happy with how the future of Game of Thrones is panning out following season seven earlier this year, but they're not yet ready to talk about the specifics of any spin-off series.

CEO Richard Plepler was asked by Variety whether he could share any details about the plans: "No... It's a fantastic group of writers and talent, most of whom have lived inside the Thrones eco-system so are very, very familiar with its intricacies.

"I think we will find with this embarrassment of riches an exciting property for us to move forward with. We are looking [at] some things, I have read a couple of early bibles and I'm excited about what I've seen."

Averaging just over 10 million viewers an episode, and breaking 12 million viewers with its record finale on 27 August, Game of Thrones season seven continued the show's incredible growth.

Its average viewership was roughly 2.5 million more than the previous season.

HBO hasn't announced anything about the final season, but The Hollywood Reporter said earlier this year that 2019 is the likely target. Showrunners David Benioff and D.B. Weiss confirmed that it will consist of just six, most likely feature-length, episodes.

There are other shows that will help HBO plug the gap as well. Westworld was a big success in 2016 and returns next year for a second season, and then there's Damon Lindelof's planned Watchmen adaptation, which work began on earlier this year.