The Batman 2 writer Mattson Tomlin has confirmed he's working on a Game of Thrones spin-off show focused on Aegon the Conqueror, saying he's currently collaborating with original author George R.R. Martin to create a historical epic.

Speaking to Entertainment Weekly, Tomlin made clear the show is still in the early stages of development but said he and Martin are working to create an in-depth profile of the legendary Game of Thrones figure akin to a piece of work on Napoleon or Alexander the Great.

"In speaking to George, it became really clear: 'This is history, treat this like it is what happened,'" Tomlin said. "Unlike the original series, I don't have thousands of pages to go off to adapt. I've got a couple hundred that I'm really focused on, and in those pages of Fire and Blood, there are a lot of clues.

"It kind of turns into doing Napoleon or doing Alexander the Great or doing some great historical figure where we know a lot about the guy. We know where he was, we know who he conquered, we know who lived, and we know who died. That all becomes the plot, and then it becomes my job to go, but what did it mean thematically? How did it feel? What were the emotions when this person died and this person lived? We don't have the context. We don't know what anybody said."

Aegon the Conqueror — officially Aegon I Targaryen — is perhaps the most influential Targaryen who laid the foundation for the world in which Game of Thrones takes place. He conquered six of seven kingdoms and was the first to sit on the Iron Throne and rule Westeros.

The Targaryens, introduced to fans through Emilia Clarke's Daenerys, have been a major focus of HBO's Game of Thrones shows. The first spin-off House of the Dragon focuses on the entire family's history, and the upcoming A Knight of the Seven Kingdoms tells the tale of Ser Duncan the Tall and his squire Egg, before he became King Aegon V Targaryen.

Tomlin's Aegon the Conqueror show has floated in and out of obscurity at HBO for some time but this is the first confirmation from someone involved that it's actually being worked on. The show first emerged in April 2023 but soon went quiet, until a report in March 2024 suggested it was back on.

HBO has otherwise found success with House of the Dragon, which kicks off its second season on June 16, 2024. In our 9/10 review of Season 1, IGN said: "After 10 episodes, House Of The Dragon has officially emerged as a worthy successor to Game Of Thrones."

Ryan Dinsdale is an IGN freelance reporter. He'll talk about The Witcher all day.