One of the characters in Castlevania 64 or Legacy of Darkness (don't remember who) said something like "don't be ridiculous, Dracula's not due to return for some time now". It is a "legend" that Dracula revives every 100 years, and that what everyone expects. But do funny things like using man-wolf power to enable Dracula to re-incarnate in a new body, and you can get him to bypass that cycle.
One thing that's a real shame is that Super Castlevania IV talks about the fact that Dracula had been resurrected "many" times every one hundred years and that there was always a Belmont to take him down, and yet Super Castlevania IV only represents his second 100 year resurrection cycle. i thought that since Lament of Innocence took place in a thousand years ago, that it was making room for several 100 year resurrections. but they decided to adhere to the "Trevor Belmont is the first Belmont to kill Dracula" line, so that didn't happen.
You know, Super Castlevania IV really gave you a sense of many many 100 year confrontations between the Belmonts and Dracula. Lords of Shadows takes place way back in the 1050s and "seems" to already have established that Dracula hates the Belmonts, making me think they go back possibly many centuries before that. Lords of Shadows might recapture some of that long family history that the canon series boxed itself out of.
I wonder if the 100 year confrontation between the Belmonts and Dracula still took place between LoI and CV III, even if the end result wasn't the Belmonts actually killing Dracula, just putting a stop to his plans during the time he was at his most powerful. Iga thought he was living quite peaceably during this time period, but I wonder.