On the Nature of Fantasy

To market a story as a fantasy story, is it necessary for magic to figure strongly in the piece, or is it sufficient for the story to take place in a setting that has magic?

I'm preparing to write a story about an apothecary, his daughter, and a blackmailer/murderer. I'd want to market this as a fantasy story if I ever tried to sell it, but, so far as I can tell, magic isn't strictly necessary to the plot. I don't, however, want to write this as a historical novel because I prefer the fantasy genre.

Any thoughts?