Woman Keeps Boyfriend's Head on Dresser, Avenges His Death

by Cheryl
(Virginia, USA)

Can you help me remember the name of this 60's or 70's horror film set in Europe I saw as a child about a man put to death by guillotine and the woman (possibly his lover) that keeps his head on her dresser?

She is overcome by instructions she 'hears' from the head to go avenge the death of the man. She seduces the men that put him to death one by one, then stabs them in the chest. I remember the film being quite disturbing as a kid - but would love to see it again with an adult perspective.

Any ideas? Thanks for your help.