This is an anthology film, hosted by Boris Karloff, who also acts in an episode called The Wurdulak. The other episodes are The Telephone and The Drop of Water.
The Wurdulak episode re-uses some of the sets from Black Sunday - the crypt and the church ruins. It's a similar type of story, but with vampires instead of witches. The horror part is mild by today's standards, but it also manages to be genuinly creepy. The film looks gorgeous, with rich colours, and is not overlit the way old films often are. It is a lot moodier than what I remember from the Hammer films. There's a scene you can't help giggle at - closeups of two persons riding what is obviously a fake horse, but then Bava himself mocks it in the final image of the film, showing how the effect is achieved.