The actress who played Regan in the The Tragedy of King Lear is not in the feature length.
A major change from Shakespeare is the passionate love between Regan and her husband, the Duke of Cornwall. Their love propels some of the extreme actions in the film.
The supporting character, Duke of Albany becomes one of the central roles in the sequel to this version of King Lear, called Memoria Draco.
A different Regan was cast in King Lear compared to in the The Tragedy of King Lear. By March over 400 had been considered.