The Volturi

In the Twilight Universe, vampires can't just run amuck, wreaking havoc in broad daylight. Well, they could, but it wouldn't be long before they'd be punished by the Volturi, the powerful coven of ancient vampires who lay down the law, and ensure that vampirism remains shrouded in secrecy. They're based in Volterra, Italy, and they're not friendly "vegetarians" like the Cullens.