Amicus Productions came out of England in 1962, but it was founded by Americans. Their horror films are a lot like Hammer, probably on purpose. The Skull is directed by Hammer stalwart Freddie Francis and stars Peter Cushing and, in a smaller role, Christopher Lee. It is based on a short story by Psycho novelist Robert Bloch, "The Skull of the Marquis de Sade", and the title of that story pretty much explains the plot. After his death, the Marquis' skull is stolen from his grave, and it carries with it an evil that travels across time to the present day (I was surprised when people in The Skull turned on lights and rode in cars ... I didn't realize we'd moved past the 19th-century prologue).
The whole thing is loony nonsense, but Cushing effectively makes us believers, at least for the 83-minute running time. (Even at 83 minutes, The Skull is stretched thin ... there's a lot of filler.) Francis gives us some ingenious looks, in particular some shots from a point-of-view inside the skull. While the effect of the skull floating ominously in space sounds silly, it's actually effectively scary. The music is by Elisabeth Lutyens, an interesting figure of some note. She was a composer of some repute, and the first woman to score a British film.
None of the above raises The Skull much beyond the norm for 60s horror, but it's reasonably entertaining.