During a recent reread of Feast, this description of the Temple of the Moonsingers (from Arya I) in Braavos grabbed my attention:
The passage is dominated by a physical description of the temple, which is pretty much as you'd expect: moon imagery, white stone, silvered dome. But what's with the large, marble maidens flanking the door? Most of what we know about the Moonsingers can be summed up in a sentence: they helped lead the ancestors of the Braavosi to a location of refuge where the dragons of Valyria couldn't find them.
The Moonsingers are also mentioned in connection with the Jogos Nhai people. Mirri Maz Duur is said to have learned birthing songs from a Moonsinger among those people. This might suggest a strong link between Moonsingers and women, but the statue is specifically mentioned as representing a maiden, not just any woman.
One particular maiden is said to have played an important role in Valyrian history, the maiden daughter of Aenar Targaryen. Everything we know about her comes from this passage in Asha's chapter, just a few chapters after Arya I:
long nail. “See here? Marwyn claims to have found three pages of Signs and Portents, visions written down by the maiden daughter of Aenar Targaryen before the Doom came to Valyria."
The topic of Aenar's daughter's visions is never given, and readers have long speculated about what she might have seen. Ideas range from a foretelling of the Doom itself to the Prince that was Promised. Is it possible that the unnamed daughter's visions could have been the basis for the actions of the Moonsingers? Did this Targaryen maiden see freedom for the slaves of Old Valyria? On a side note, this would provide an interesting historical parallel for Dany's actions in the cities of Slaver's Bay.
The first Samwell chapter of Feast mentions an old book that Sam discovers in the vaults of Castle Black, Dragonkin, Being a History of House Targaryen from Exile to Apotheosis, with a Consideration of the Life and Death of Dragons by Maester Thomax. As far as I can tell, this seems to be the only source of information telling us how House Targaryen came to leave the Freehold for Dragonstone: exile. Could House Targaryen have been exiled from Valyria for inciting, supporting, or otherwise being involved in a slave uprising or the exodus of the founders of Braavos?
It makes little sense for a family of proud Dragonlords to move their seat to Dragonstone, a tiny island on the edge of a (slaveless) backwater Valyria never bothered to conquer, of its own accord. If Aenar Targaryen's daughter had simply foreseen the Doom, the House could have relocated to a richer area beyond the reach of the catastrophe. And then there's the matter of exile. A poor, isolated location on the fringes of Valyrian influence would have been the perfect destination for an exiled noble family.
We know that the Braavosi hold slavery in disdain to this day, and talk of dragons is always taken seriously there. Why, then, would the Sealord himself witness a secret marriage pact between the Martells and the surviving Targaryens with the goal of restoring the ousted dynasty to power? Perhaps the Targaryens have a history of sympathy toward or friendship with the ancestors of the Braavosi.
There are problems with the attempt to link up all of this disparate information. We have no idea of when Aenar Targaryen and his daughter lived, except that it predated the Doom. Braavos was founded (and remained secret) centuries before the Doom, so Targaryen assistance to the Braavosi would have also remained secret for a long time. If Maester Thomax's book is correct, and the Targaryens were exiled to Dragonstone as punishment, why were they permitted to take dragons or eggs with them? Why were they not wiped out for undermining the economic core of Valyria?