'Game of Thrones' Spinoff Just Got a Major Update

One of the Game of Thrones spinoff shows just got a major update – especially considering it was little more than a rumor before. Development of a series about "Aegon's Conquest" is heating up, with writer Mattson Tomlin heading the project, according to The Hollywood Reporter. The series still has not been greenlit, but the chances of it going into production are much more promising now.

Aegon's Conquest would be a prequel to Game of Thrones and even a prequel to House of the Dragon. It would tell the story of King Aegon I Targaryen conquering Westeros and uniting the Seven Kingdoms for the very first time, possibly answering some questions about House Targaryen's prescience and other magic in the process. Up until now, this project was only a rumor, with less to go on than other spinoffs in development such as The Sea Snake or the Jon Snow sequel. Now, insiders say it looks more promising.

Sources familiar with the project told THR that HBO is focusing on Aegon's Conquest in an effort to take a "back to basics" approach to the Game of Thrones franchise. It would be just as easy to adapt as House of the Dragon, since both draw on material from George R.R. Martin's fictional history book Fire & Blood. That book begins about 300 years before the events of Game of Thrones, documenting House Targaryen's invasion of Westeros, and describes their rise in a historical context.

The idea of a series about Aegon's Conquest has been popular among some fans for years, though it was not in the initial batch of spinoffs HBO was working on after Game of Thrones ended in 2019. There were no reliable reports about this project until the summer of 2023, when it was reported by Variety. Additionally, House of the Dragon showrunner Ryan Condal had mentioned the idea of this adaptation in 2022 when his show first premiered.

It's unclear which of the shows we have heard about are still on the table right now and which ones have been set aside. In a recent blog post, Martin explained that The Sea Snake has been changed from live-action to an animated series. It's been over a year since we heard any updates about SNOW, a potential sequel set after the events of Game of Thrones. Work is now underway on A Knight of the Seven Kingdoms: The Hedge Knight – the second spinoff to be greenlit.

Aegon's Conquest is described in Martin's books The World of Ice and Fire and Fire & Blood. About 100 years earlier, the "Doom of Valyria" destroyed all other dragon-riders and their civilization, leaving House Targaryen as the last to wield this power on their island, Dragonstone, off the coast of Westeros. Though previously uninterested in the Seven Kingdoms, they decided abruptly to take over the entire continent. According to House of the Dragon, they did so after Aegon I had a prescient dream about the return of the White Walkers.

The show would likely center around Aegon and his two sister-wives, Visenya and Rhaenys. It would also include their bastard brother, Orys Baratheon, who would become the founder of the noble house which becomes a major power in the later series. The show would also give fans a glimpse of Westeros before the conquest, when House Durrandon ruled Storm's End, House Gardener ruled the Reach and House Hoare still ruled over the Riverlands from Harrenhal on behalf of the Ironborn. Along the way, this show could answer some major questions, including how much Aegon may have told Torren Stark, the last King of Winter about his vision.

Martin's books are available now in print, digital and audiobook formats for those who want to read ahead and prepare. Game of Thrones and House of the Dragon are streaming now on Max. House of the Dragon Season 2 premieres this summer, while A Knight of the Seven Kingdoms is currently in production.