I've notice that "Vulthuryol" parallels the dragon "Smaug" off the Hobbit, the dragon that conquers and later lives in underneath the Lonely Mountain after the Dwarves have fled from it.
In lack of Skyrim lore, because it is impossable any other way, Vulthuryol had to be "smaller" at least younger to get into BlackReach, a Dwemer keep. Which I imagine he destoryed... but went into a rest after killing off all the Dwemer (Dwarves).
He is also a reddish drake (another quality of Smaug). In belief he arrived a young dragon and now is an old and arrogant dragon of his power (he is fairly weak and doesn’t fly)… Anyone else make this connection?