User blog comment:Zippertrain85/Harkon's backstory?/@comment-9062114-20130506154321/@comment-3217145-20130507002541

Whiterun and Windhelm were built before the First Era, and they're further from the coast than Solitude is. Winterhold was built in the early First Era. Merely conjecturing "Solitude probably wasn't built yet" isn't really evidence, since it's not based on any actual information. Besides which, the Volkihars could have become vampires before Solitude existed, and it was built before Serana was sealed up. Or maybe they weren't. I not have enough information to say.

The "centuries" thing probably is lazy writing, choosing an arbitrarily big number since they didn't decide exactly how old the Volkihars were and "centuries" would be accurate no matter what. Whiterun is referred to as being "centuries" old too, I think, but it's thousands of years old since it's from the Merethic era.

The reason I say Serana is from the First Era is from specific in-game dialog. When you first meet her, you mention the Empire to her. She says "what empire?", you say "the Cyrodiilic one," and she says "there's an empire in Cyrodiil?" There's been an empire in Cyrodiil since the third century of the First Era. When or where could she be from that she wouldn't have heard of it? Though I guess if you're planning to write a blog, it wouldn't make much sense to answer that question here.