User blog comment:Soldierscuzzy/Got Questions? The Dragon's Dogma Developers Have Answers/@comment-97.93.102.19-20120624031441/@comment-97.93.102.19-20120624205454

I'm not entirely convinced of that due to some issues/strangeness in the way things are presented. For one, as I said, the dragon in the prologue, the one we kill, and the one we apparently can become all are physically identical, and the prologue and game dragon have identical voices when the Seneschal would have had to have killed it. Keep in mind, the Ur-dragon, a minor character in comparison, has its own unique voice actor.

The dragon knew the history of the Tainted Mountain, even though it has been in ruins even before the current Seneschal in the prologue.