Why do vampires appear as earl and duke in movies?

Vampires are not all fiction. Vampires come from an ancient and mysterious race. Modern science generally believes that vampires are a disease, and the most obvious symptom is bloodthirsty, which is hereditary. European titles are hereditary, so if the ancestors of vampires have titles, then vampires as descendants naturally have titles.

In addition, this is also a cultural phenomenon, just like in China, fortune tellers are always blind, zombies always wear clothes of the Qing Dynasty, female ghosts always criticize their heads, and stars always have hair dia.