Rhaenys the Dreamer:
Rhaenys the Dreamer is my most* original theory, there are elements and individual pieces that I have seen others bring up before, however I have never seen anyone compile everything together into one coherent theory, only individual ideas by different people. If you HAVE heard this before, I have been commenting versions of this for years on tiktok , some of which have received 20-80k likes, so it may be have me and I wanted to catalog my theories, if I am accidentally directly quoting someone else, I am sorry. Art cited.
My theory relies on a few theories, but essentially, Rhaenys was the Dreamer who saw the song of ice and fire, and told Aegon. I do believe that Aegon could have also probably a Dreamer, however, there are seemingly patterns of the male dreamers having a harder time interpreting their dreams correctly. This part is me agreeing with @hallowed-harpy and all of her videos on womanhood, fertility, the dragons and female vs male dragon dreamers, so instead of repeating why I think it makes more sense for it to be Rhaenys, you should just check out her content. My theory relies on the implications on this, but not her being a Dreamer just in itself, there's more!
Women had different roles in Valryian culture than they did in Westeros, and where it may have been Rhaenys who was the one to make sense of the dream (we've seen siblings having the same dreams in other generations ei: Maester Aemon and Daeron the Dreamer), it could have been agreed upon that the idea of the conquest be told to be Aegon's.
Aegon was a dragon:
"Man wants to be king o' the rabbits, he best wear a pair of floppy ears"
"The petitioners will soon be at my gates. I must don my floppy ears, and become their Queen once again" - Daenerys
The rabbits here are symbolic of people Daenerys wishes to rule, but doesn't share culture with, so she felt the need to 'don floppy ears' by her distain for wearing a tokar and it's tie to slavery.
Valryian culture is different to Andal or First Man cultures, we know that some of the dragons are named after Valryian gods, but Aegon flew to Old Town and adopted Andal customs, such as knighthood, as well as embracing the Faith of the Seven, which is the predominant faith in the realm. He was crowned by the head of that faith, and Westerosi precedent followed suit.
Aegon would've likely understood that the Kings in Westeros followed Andal tradition already, from the Targaryens having lived near by, and acted as the head of the conquest to try to negotiate more peaceful surrender to Westeros. If they told any story, it would be written as Aegon's. We know that both Rhaenys and Visenya sat on the Iron Throne while he wasn't, they were not treated lesser than Aegon, so I hope it isn't a stretch saying the three would not have minded this optic in sane of the goal to be able to unite all of the realm.
So, if she IS the Dreamer,
why would it matter?
All three dragon riders fought in the conquest, all three were perfectly able to fight on their own..
Aegon had the Valryian steel sword, Blackfyre, whereas Visenya had the Valryian steel sword, Darksister. We are told that Rhaenys never had a sword because she wasn't a fighter, and that could make sense, until I think about the fact that Valryians would've remembered about the Scorpion bolts that were evolved from the Rhoynish history combating with dragons. If something were to happen to her dragon, it wouldn't make sense for her not to have SOME form of a weapon to protect herself, maybe not a sword but something smaller, such as a dagger.
George RR Martin directly acknowledged the concept of Aegon's dream on House of the Dragon, claiming there has been speculation so, let me speculate: if he is acknowledging that the concept came from him, and not just it coming from the show only, why is the dagger so involved? The catpaw's dagger isn't confirmed in the books to have Valryian glyphs, but it IS Valryian steel, and this relies on the theory of them being revealed somehow in the future.
My theory is suggesting that it makes more sense that Aegon had Blackfyre, Visenya had Darksister, and Rhaenys had the Dreamers dagger (rather that Aegon having a sword and a dagger, and Rhaenys having nothing while by herself)
So what happened?
Rhaenys gets shot down out of the sky when a bolt enters Meraxes' eye and they plummet to the ground. Is there a chance that Rhaenys could have survived such a fall? Yes, actually.
"When Meleys closed her jaws around Sunfyre's neck, Vhagar fell upon them from above, causing the three dragons to fall to the earth. Although Vhagar rose unscathed, Meleys was slain and Sunfyre had one wing half torn from his body. King Aegon, grievously injured and burned from the encounter, was taken to King's Landing to recuperate. Unable to fly and too huge and heavy to be moved, Sunfyre remained near Rook's Rest to allow him time to heal. " - Fire + Blood, the dying of the dragons.
Rhaenys was shot down in the sky, and it is possible that she survived.. but I think that there is another parallel at play here, Maester Aemon.
Although, she could've been alive when they discovered her, I theorize she was probably dying of her injuries, whether in shock or not.
When Maester Aemon is dying, he starts talking about the dragons, the prophecy, and eventually thinks about Egg.
"Dragons," Aemon whispered. "The grief and glory of my House, they were." "I see them in my dreams, Sam. I see a red star bleeding in the sky. I still remember red. I see their shadows on the snow, hear the crack of leathern wings, feel their hot breath. My brothers dreamed of dragons too, and the dreams killed them, every one. Sam, we tremble on the cusp of half-remembered prophecies, of wonders and terrors that no man now living could hope to comprehend...or..." "...or not." Aemon chuckled softly. "Or I am an old man, feverish and dying." He closed his white eyes wearily, then forced them open once again. - Maester Aemon to Samwell
The crux of my theory is this:
What was in the letter?
Rhaenys was the Dreamer, or at least another Dreamer who was capable of interrupting the dragon dreams. When she was shot out of the sky in Dorne, she may not have died right away, but was laying dying and worried about the prophecy, telling who ever was there to discover her.
When Aegon is presented with a letter from the Princess of Dorne, all we know it that he grips the throne so hard, he bleeds, it's the only time he does and he burns the letter. What if what was in the letter... was Rhaenys' dagger. Since he fled to Dragonstone, it could be possible that the Dornish told Aegon what Rhaenys had told them about the Song of Ice and Fire in order to get him to trust them that they actually talked with her, and he may have reluctantly agreed to stop his revenge on the agreement that Dorne would side with Westeros and participate in the Long Night with them, as long as they kept their autonomy.
This is my first written out and cited theory, so I absolutely will unpack this more, include more direct references, but I had a house fire in 2025 and currently do not have the physical books to easily pull my quotes from. 🫶
