Blacula is one of those films from the 1970's that just makes you scratch your head and say, "what‽"
In it, a prince from Africa (because, Africa isn't big or anything. No need to specify.) goes to Romania to meet Count Dracula in the 1780s to ask for his help combating the slave trade.
See? You're scratching your head already!
Anyway, he is promptly turned into a vampire and locked in a coffin. The coffin doesn't open until the 1970's when it's somehow in Los Angeles. Because, I mean, duh. Right? There's not really much to say. Blacula pops out of the coffin, sucks blood, makes a bunch of vampires, falls in love (vampires wear their hearts on their sleeves), is pursued by police, eventually loses his girlfriend, and decides to commit vamp suicide by going outdoors in the daytime.
Though, now that I think about it, if you want to watch a movie with a black vampire, Blade is far superior. Even if technically, he's really a dhampir.