Tower Of London (1962)

Starring Vincent Price, Michael Pate, Joan Freeman, Robert Brown, Bruce Gordon
Directed by Roger Corman
(actor & director credits courtesy IMDB.com)

On the death of his brother, the king of England, the hunchbacked Richard of Gloucester plots and murders to seize the throne for himself, but is haunted by the ghostly apparitions of his victims.

It's difficult not to compare this adaptation of the story of Richard III to the 1939 version starring Basil Rathbone, which also featured Price in a lesser role.  Rathbone's version is the superior film in my mind, but the way the screenplay for this film casts Richard in a re-imagining of Shakespeare's MacBeth is interesting.  Price is good, playing a figure not dissimilar to some of the vile characters he played during Corman's Edgar Allan Poe cycle, and his supporting cast is accomplished as well, but Rathbone's Richard was a craftier villain, and Pate's role as henchman to Richard in this version, is far less memorable than Boris Karloff's executioner in the first film.