There's finally some exciting updates about the in-the-works Aegon's Conquest spinoff series from writer Mattson Tomlin, and it's exactly what we have been hoping to hear about the next possible Game of Thrones offshoot series. While HBO still hasn't officially ordered the spinoff to series, Tomlin revealed he's still hard at work on the show and it has a certain someone's seal of approval.
The spinoff series has been in development since HBO was first eyeing another GoT offshoot back in April 2023, and things started to "heat up" for the Aegon's Conquest series last year. It's no secret that fans have been wanting to watch the major piece of Westerosi history come to life on screen since it's really the beginning of everything and set the whole series into motion.
On July 30, Tomlin interacted with fans on social media and answered a number of pressing questions about the projects he has in the works. Obviously, fans inquired about the Aegon's Conquest series, and with only two one-word answers, Tomlin managed to reveal quite a bit of information, including that he's still working on scripts for the potential spinoff.
— mattson tomlin (@mattsontomlin) July 31, 2025
On top of sharing that he's been writing "LOTS" on the spinoff series' scripts, Tomlin also revealed that A Game of Thones author George R. R. Martin has been involved in the creation of the Aegon's Conquest show. When asked about whether Martin had a hand in the spinoff, Tomlin simply replied with "Yes." That's definitely a sigh of relief for book fans knowing that the author's already on board!
— mattson tomlin (@mattsontomlin) July 31, 2025
The planned spinoff series would take place before the events of House of the Dragon, marking the next prequel property in the Game of Thrones franchise. The Aegon's Conquest series, which doesn't have an official title just yet, would focus on Aegon the Conqueror, also known as Aegon I Targaryen unifying the Seven Kingdoms with help from his sisters/wives Rhaenys and Visenya. As fans know, there are seemingly endless battles in this particular story that have yet to be adapted.
Who doesn't want to see even more of the Targaryen Dynasty's beginnings? Judging by the success of House of the Dragon, HBO should definitely give the Aegon's Conquest series the green light, especially if the current prequel series will end with season 4 as has been suggested. Of course, fans still have the upcoming prequel spinoff series A Knight of the Seven Kingdoms, which is coming to HBO in 2026 (after being delayed from a release in late 2025).
Since the Aegon's Conquest series hasn't been formally ordered by HBO just yet, there are no additional details about who would play Aegon the Conqueror or even how many episodes the series would have. But Tomlin's recent updates are incredibly promising about the prospect of the show getting an official pick-up. There have been plenty Game of Thrones spinoffs in the works over the years, but this one might be the most-wanted among fans. Thankfully, they aren't rushing it.
Stay tuned for more news and updates from Winter is Coming!