A second getting a pilot order, and will reportedly focus on the history of House Targaryen 300 years before the original series begins - and around a century after the Doom of Valyria. This cataclysmic event completely shifted the history of Game of Thrones world, creating a power vacuum in Essos and leaving the remaining Targaryens in search of a new land to conquer.
While the time frame of this new series (which is based on George R.R. Martin's book Fire & Blood) would place the series around the time of Aegon I's conquest of Westeros, the show could also reveal other major moments from the Targaryens' history. The Dance of Dragons (a Targaryan civil war) is a firm favorite, and the Blackfyre rebellion or the history of Daenerys' eggs are also strong contenders - and all excellent ideas.
While the Doom of Valyria is undoubtedly one of the most important events in Game of Thrones' timeline, it's one that the original series chose not to show, even though there were flashbacks to other historical scenes like the "birth" of the Night King and the fall of the Mad King. Even though this new Game of Thrones prequel will be focused on the Targaryens, the Doom of Valyria may be better left off-screen.
The Doom of Valyria Explained
A hundred years Targaryens, who left for Dragonstone before the Doom, warned by a prophetic dream.
Valyria's Story Is Too High Fantasy For Game Of Thrones
Although the Doom is a fascinating part of this history, and many fans would love to see Valyria at the height of its magic, it's really too high fantasy to really work as a Game of Thrones prequel. One of the things that appealed about Game of Thrones was that it felt very much like historical drama with a little bit of magic thrown in. Valyria is the opposite - a whole lot of magic and mystical beasts, with some long gowns thrown in for good measure. While it may not have the elves and dwarves of Lord Of The Rings, it moves into similar territory - and with Amazon's Lord of the Rings series on the way, creating a competitor high fantasy television show isn't a smart move. Valyria is also so different to the Westeros that fans know and love that this would essentially be creating a whole new universe - something that doesn't really appeal to those looking forward to returning to a familiar world.
It's Too Difficult For HBO To Do Properly
Even if the Fire & Blood spinoff took that gamble and went full dragonrider, the bigger issue is that in a world with such extensive lore, the decision to keep the Doom of Valyria shrouded in mystery is a very conscious one. Choosing to make something up for this would and turn it into a series that explains the Doom would be almost disrespectful to the world that Martin has created. Valyria has an almost Atlantean thrill to it, and explaining the Doom would ruin the mystery that makes it special. Was the Doom man-made, by over-confident fire mages? Was it the judgment of the Gods, or a natural disaster? Fans don't actually want to find out.
This would also require writers to essentially create the world from near-scratch, as very little is known about Valyria (comparatively speaking). As Game of Thrones proves, Martin's world is one that may well unravel when it isn't being built on the work of Martin himself, and no one wants to see a prequel series with the kind of sloppy writing that characterized the final few seasons of Game of Thrones. Add in the cost of production for a world that is filled with tall spires and palaces, rivers of fire, magic at every turn, and dragons crowding the skies, and it just doesn't make any sense to gamble on something this big, when there are so many other incredible options to choose from.