With a massive world and a history that goes back 12,000 years, it's no surprise that Game of Thrones is the subject of four proposed spin-off shows. The subject matter of these planned spin-offs is still a mystery, but author George R.R. Martin may have just given us a hint about one.

Martin took to his blog today to preview his newest companion book to his Thrones saga called Fire & Blood. This new novel will cover "all the Targaryen kings from Aegon I (the Conquerer) to the regency of Aegon III (the Dragonbane), along with their wives, wars, siblings, children, friends, rivals, laws, travels, and sundry other matters," Martin writes. "Oh, and there are dragons too."

Aegon the Conqueror has been named dropped countless times throughout the Game of Thrones series. Even if you haven't scoured the Wiki pages for info on Aegon and his descendants, you still probably know that he was a key cornerstone of Westerosi history and a distant ancestor of Daenerys Targaryen (Emilia Clarke). He's so important, in fact, that we wouldn't be surprised if HBO decided to build a spin-off around his conquest of Westeros — and it sounds like Martin thinks so too.

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"As most of you know, HBO is presently developing a number of different prequels to Game of Thrones," Martin says on his site. "I know I am going to be asked whether those shows are going to be based on material from Fire & Blood. It's a logical question. The only answer I can give is... ah, well, no one is sure yet, and anyway, I am not allowed to say. So let's move that to the side."

Bring on the dragons, HBO!

<em>Game of Thrones</em>Game of Thrones