HBO is reportedly developing a prequel about Aegon’s Conquest, and House of the Dragon’s big Game of Thrones retcon must be key to the show’s story.

HBO is making a Game of Thrones prequel about Aegon’s Conquest, but it faces some potential challenges after one retcon from House of the Dragon. Game of Thrones‘ ending may have been divisive, but that hasn’t stopped HBO from exploring Westeros further on the small screen. House of the Dragon was but the first step towards expanding the franchise, with many more spinoffs expected.

Besides House of the Dragon season 2, there is also A Knight of the Seven Kingdoms: A Hedge Knight, which has a series order, as well as others that have not yet been confirmed. Among those, HBO is developing an Aegon’s Conquest spinoff, which means audiences will be able to see exactly how the Targaryen dynasty was established. Importantly, that includes the real reason Aegon conquered Westeros in the first place.

Game Of Thrones’ Conquest Spinoff Will Have To Include Aegon’s Dream

House of the Dragon’s retcon cannot be ignored.

There are several key events that an Aegon’s Conquest spinoff would need to take from George R.R. Martin’s books, but one of the biggest elements of the show isn’t (yet) part of the author’s work. Instead, it comes from House of the Dragon season 1: Aegon’s dream of the White Walkers. Called A Song of Ice and Fire, the Conqueror’s prophecy foretold a coming darkness that would envelop all of humanity, and only a Targaryen on the Iron Throne could stop it. This, it turned out, was why he conquered Westeros.

Aegon’s dream was never mentioned in Martin’s own A Song of Ice and Fire novels, the Targaryen history book Fire & Blood, or Game of Thrones, making it a massive retcon of Targaryen history by House of the Dragon. Because of that, then there’s no way the Aegon’s Conquest spinoff can ignore it. It’s now intrinsic to the character and to the entire Targaryen dynasty, as much a part of the story as him unifying Six of the Seven Kingdoms (with Dorne resisting), having the Iron Throne forged, and beginning a line of Westeros King’s and Queens that lasts almost 300 years.

What Aegon’s A Song Of Ice And Fire Dream Means & How It Changes Game Of Thrones

The prophecy has a big impact on Westeros and the Targaryen dynasty.

Aegon the Conqueror’s A Song of Ice and Fire has a major impact on pretty much every era of Game of Thrones history that follows it. It changes the Targaryen dynasty, since almost all kings would have been aware of it – even if some didn’t believe it. That much is clear – and part of the point of it – in House of the Dragon, where Aegon’s dream (and its conflation with The Prince That Was Promised prophecy) becomes a key catalyst for the Dance of the Dragons, and from a misunderstanding at that.

In terms of Game of Thrones season 8, it’s also possible to see the impact of Aegon’s dream. Since the point of the Conquest was that a Targaryen was needed to defeat the White Walkers, it suggests Daenerys Targaryen was never going to be Queen for long, since their purpose was fulfilled. Likewise, it supports the idea of Jon Snow and/or Daenerys being The Prince That Was Promised, while adding more weight to the fact that the catspaw dagger – Aegon’s knife, which carries the prophecy – was used to defeat the Night King.

There are other events not covered in as much detail the dream could apply to as well. It’s possible the Mad King knew about the White Walkers, and it’s part of what drove his actions. Perhaps A Song of Ice and Fire is why King Aegon V Targaryen was so desperate to bring dragons back that he ended up killing himself and multiple others in the Tragedy at Summerhall, which could be shown in the spinoff A Knight of the Seven Kingdoms. It reshapes so much of canon, which means it definitely can’t be ignored.

House Of The Dragon’s Targaryen Prophecy Set Up A Very Different Aegon Conquest Show

Aegon is now more than just a conqueror.

Prior to House of the Dragon, Aegon’s Conquest was primarily a story of unstoppable power and ruthless ambition. Aegon had already helped put an end to the power struggles in Essos, and the young Lord was hungry for more – turning his attentions to Westeros from his family’s seat of Dragonstone. With his dragon, Balerion the Black Dread (still the biggest to have ever lived), and those of his sisters – Vhagar (who belonged to Visenya) and Meraxes (Rhaenys’ dragon) – as well as an army, he took control with fire and blood.

Aegon’s dream changes that to some degree. This is not just the story of an ambitious conqueror aiming to take power, but of a would-be hero who believes himself the savior of the entire world. That doesn’t mean ambition and a thirst for power aren’t still there, but they’re just part of why he comes to Westeros now. Game of Thrones‘ Aegon’s Conquest spinoff will instead see him much more as the hero of his own story, a man burdened by destiny. It’s more complex and, really, more interesting, given how relatively easy the conquest is for him, though there is a problem too.

Game Of Thrones’ Long Night Disappointment Could Be A Problem For HBO’s Aegon’s Conquest Show

Season 8’s White Walker story left a lot to be desired.

The biggest problem with Aegon’s Conquest being driven by his dream of the White Walkers and The Prince That Was Promised prophecy is the same issue with House of the Dragon including it: it’s all weakened by Game of Thrones‘ ending. The expanded universe may be turning the Targaryen dynasty into a 300-year preparation for the coming battle between the living and the dead, but it’s one that the main show ended swiftly and without many answers in season 8.

After years of build-up, the White Walkers were defeated within just three episodes. The second Long Night was, in the end, pretty darn short. There was no real confirmation about The Prince That Was Promised prophecy, and Jon Snow didn’t get to kill the Night King. This is what Aegon’s Song of Ice and Fire is setting up and, while it’s potentially great for the individual show, it is hard for it to avoid the fact that so many were disappointed with how Game of Thrones finished that story.

The Aegon’s Conquest spinoff can’t help but be about the prophecy, but it needs to find the right balance, ensuring it’s contained and works within its own narrative and there’s a satisfying story alongside it. Aegon, of course, never faces the White Walkers, but there should still be a sense of conclusion for his arc with regard the prophecy – whether that’s simply showing him passing it on, or ruminating on his own concerns about the future or perceived failure to deal with the threat. It can’t just be impactful for Game of Thrones, or it’s going to have a clear problem.