The Origin of Dunk and Egg/Aerion??? (Spoilers Extended)

Background

With the first season of A Knight of the Seven Kingdoms set to air later this year, I got curious about the origins of the series and so in this post I thought it would be interesting to look back and discuss the origins of the Dunk and Egg series.

ETA: Sorry for the somewhat weird post name, it was a placeholder and I forgot to update before I submitted.

Character/Plot Origination

The Hedge Knight came out as a part of the Legends anthology in 1998 and introduced the world to Dunk and Egg. In a 2019 interview GRRM elaborated on how he came up with the idea:

Q: At what point did you start to write outside the confines of A Song of Ice and Fire? I’m thinking here of the Dunk and Egg, “Hedge Knight” stuff, because that was published quite early. Was that conceived as part of this story that just didn’t fit? How did that come about?

GRRM: Robert Silverberg decided he was going to do an anthology called Legends, which consisted of original stories. He wanted ten fantasy writers each writing a story in their fantasy world—an original story, never before published. He was offering what was quite a substantial advance, I think a record advance for a story in any anthology. And his lineup was amazing—Terry Pratchett and Stephen King were going to be in this, and Anne McCaffrey, and all of the bestselling fantasy writers. I was just getting into my series then. I really didn’t belong in that number, but I knew that I wanted to be in this book. So, when he invited me to be in this book I gleefully accepted. And then I had a think. “Well, what am I gonna write for this book?” I’m still in the middle of writing A Clash of Kings—the only book out then was A Game of Thrones. “Am I gonna write a story about Tyrion or Arya or Jon Snow? No, I can’t do that. I have to save that for the book. I have to do a prequel.” So I started thinking about my history and what would be a good area to write in and I came up with the Dunk and Egg stuff. I was particularly attracted to the whole story being built around a tournament. I love medieval tournaments—reading about them, writing about them. There are, of course, some of them in the main books, but this was an opportunity, in a time of peace not war, to look at a medieval tournament with all its pageantry, the jousting and the combat, and reveal a little of Westerosi history. And like many other things, it grew. I gardened it, I started it, and suddenly it was all there. -SSM, In Conversation with GRRM (Dan Jones): Aug 2019

Aerion Brightfire

With GRRM not adding the Blackfyres/fleshing out the Targaryen family tree until 1999, it is possible that the original foil for D&E (and potentially the future Targaryen claimant) was actually Aerion sons:

Aerion Brightfire did not stay in Lys all his life, only a few years. He may have fathered a few bastards there, which would mean Dany has "relatives" of a sort in Lys... but they would be very distant relatives, from the wrong side of the blanket. -SSM, Many Questions: 14 Oct 1998

If interested: The Original Cloth Dragon: The Sons of the Bright Prince & Aerion Brightflame: Connecting the Dots

TLDR: GRRM came up with D&E because he needed a good story to be a part of the Legends anthology set. He decided upon something regarding the pageantry of a tourney during peacetime. While not confirmed, at the time GRRM had not come up with the Blackfyres, so it is possible that Aerion's descendants were the original foil for this series (and could still continue to be, ex: Brightfyre).