The realm of King Arthur is an oftenly well known fantasy world. You would be at least a little hard-pressed to find someone who didn't know of Camelot, Merlin, King Arthur and Excalibur. Roleplay as anyone, even OCs, with a few exceptions.
Vampires are attacking Wizards, as their queen i must solve the problem or face Azkaban. The only solution, to marry some wizards. The problem, the Wizards i have in mind have always hated me. (Needing a Severus, Lucius, & Draco)