As far as we know, there are still multiple Game of Thrones spin-offs in the early planning stages at HBO, including a series based on George R.R. Martin's The Adventures of Dunk and Egg, and a sequel show about the continuing adventures of Jon Snow.
Only a handful (if that) of these projects are expected to be given the green-light, however, and it seems the massive success of House of the Dragon has led to the network prioritizing another prequel series focusing on the Targaryens.
According to THR, The Batman co-writer Mattson Tomlin is currently penning an adaptation of Aegon’s Conquest, which charts the Targaryen’s bloody and brutal conquest of Westeros prior to the events of House of the Dragon.
The story follows the invading Aegon Targaryen and his sister wives, Rhaenys and Visenya, who conquered Westeros with their mighty dragons. The trio successfully unified six of the Seven Kingdoms in just two years, with only Dorne managing to resist.
The project is said to take a “back to basics” approach to George R.R. Martin’s epic fantasy universe.
House of the Dragon launches its second season this summer (find out more below), and A Knight of the Seven Kingdoms: The Hedge Knight is set to begin production this year.
"The prequel series finds the Targaryen dynasty at the absolute apex of its power, with more than 15 dragons under their yoke. Most empires—real and imagined—crumble from such heights. In the case of the Targaryens, their slow fall begins almost 193 years before the events of Game of Thrones, when King Viserys Targaryen breaks with a century of tradition by naming his daughter Rhaenyra heir to the Iron Throne. But when Viserys later fathers a son, the court is shocked when Rhaenyra retains her status as his heir, and seeds of division sow friction across the realm."
House of the Dragon season 2 sees Matt Smith, Olivia Cooke, Emma D’Arcy, Eve Best, Steve Toussaint, Fabien Frankel, Ewan Mitchell, Tom Glynn-Carney, Sonoya Mizuno, and Rhys Ifans reprise their respective roles. Additional returning cast members include Harry Collett, Bethany Antonia, Phoebe Campbell, Phia Saban, Jefferson Hall, and Matthew Needham.
New recruits are Clinton Liberty as Addam of Hull, Jamie Kenna as Ser Alfred Broome, Kieran Bew as Hugh, Tom Bennett as Ulf, Tom Taylor as Lord Cregan Stark, Vincent Regan as Ser Rickard Thorne, Abubakar Salim as Alyn of Hull, Gayle Rankin as Alys Rivers, Freddie Fox as Ser Gwayne Hightower and Simon Russell Beale as Ser Simon Strong.
The directors for the new season are Alan Taylor (Episodes 1 & 4), Clare Kilner (Episodes 2 & 5), Geeta Patel (Episodes 3 & 8), Andrij Parekh (Episode 6), and Loni Peristere (Episode 7).
An exact season 2 premiere date has yet to be announced, but House of the Dragon will return for its second season next summer.