House of the Dragon: Casting is underway for Game of Thrones prequel series

New show's storyline will take place 300 years before the events of 'Game of Thrones'

Casting is reportedly underway at HBO for its Game of Thrones prequel series.

According to Insider, the network has begun casting for House of the Dragon. This is one of the few developments made since the successor show was first announced last year.

In October, HBO revealed that fans could expect a 10-episode “straight-to-series order” for a Targaryan-centric prequel show co-created by Miguel Sapochnik and Ryan Condol.

The prequel will be based on George RR Martin’s Fire & Blood books which are set 300 years before the events of Game of Thrones.

Sapochnik will direct the pilot as well as additional episodes throughout the series. The director is best known for his battle-centric instalments including the two most action-packed episodes of Game of Thrones's final season, “The Long Night” and “The Bells”.

There is no concrete news on when exactly House of the Dragon will air. Last year, the network’s programming president Casey Bloys told Variety that his “guess” is sometime in 2022.

House of the Dragon is one of four Game of Thrones spin-offs in the works at HBO. An untitled prequel starring Naomi Watts was not picked up by the network for a full series in October 2019.

Of the failed prequel pilot starring Watts, Bloys has previously said: “In development, in pilots, sometimes things come together, sometimes they don’t."

Bloys also praised the pilot’s showrunner Jane Goldman, remarking that Goldman took on the challenge on “beautifully” and that “there was a lot more world creation [involved] because she set hers 8,000 years before the show, so it required a lot more".

He added: “One of the things about House of the Dragon, there is a text, there is a book so that made it a little bit more of a road map for a series order."