"If I tell you, they may need to kill you too." Marwyn smiled a ghastly smile, the juice of the sourleaf running red between his teeth. "Who do you think killed all the dragons the last time around? Gallant dragonslayers armed with swords?"
"Tell them how good they are ... but say nothing of prophecies or dragons, unless you fancy poison in your porridge."
Marwyn seems to indirectly confirm that it was the maesters who killed the last Targaryen dragons, and that it was through poisoning. He laughs off the idea that it was done with traditional weapons. There's also the possibility that having them kept in the dragonpit had some effect, but it seems like this would really only inhibit their growth. I don't think it would make them deformed, like the last dragon apparently was. There's also the relative speed at which the dragons died. Animals that survived for thousands of years in Valyria couldn't hack a century and a half in Westeros. And I remember seeing some theory on here that suggested it was poison that killed Balerion, although I can't remember exactly where or what evidence was brought up.
Another possible implication of this is that it shoots a bigass hole in Septon Barth's (aka Jaehaerys I's Hand of the King) book. "Death comes out of a dragon's mouth, but death does not go in that way." Well, um, if the dragons were poisoned, and poison is almost always meant to be ingested, then yeah death can go in through a dragon's mouth. Barth's proposed method of killing a dragon — stabbing it through the eye — is sort of the means that Marwyn laughs off ("gallant dragonslayers with swords"). I've said this before, but I really think that Barth's book is propaganda and that the "Death of Dragons" book in the Citadel is the "real" story. Which means that anyone taking Barth's book as fact — like, maybe, Tyrion — is getting (likely) inaccurate information.
Edited by Apple Martini, 23 April 2012 - 11:50 AM.