It's difficult for me to associate a perfume with medieval times or with gothic stuff. Maybe it's because I like dark perfumes but am not into the goth stuff? The one perfume I highly associate with the (modern) goth look is Kingdom. I don't like this scent though, and I don't think it's dark either. It just sits on my skin and takes over it, no development or interaction. Just like those goth kids who wear the exact same clothes for about 5 years in a row (hope I am not insulting anybody here, I have nothing personally against this fashion style, this is just what Kingdom makes me think of...).
Caron, in my opinion, is the ruler of dark scents. They do it in such a magnificent manner. The Caron perfumes are so complex and most of them have a dark, dense base. They are not medieval though.
My favourite dark scents include quite a few Carons (and I haven't tried their entire line yet...):
Nuit de Noel (Caron) - parfum
N'Aimez que Moi (Caron) - parfum
Tabac Blond (Caron) - parfum
Narcisse Noir (Caron) - parfum only, the EDT is too cheerful
Youth Dew (in parfum only)
Feuillles de Tabac (Miller Harris)
Arabie (Serge Lutens)
Muscs Kublai Khan (Serge Lutens)