The film was meant to star Marlon Brando. He wanted a study of Edwin's tragic life (a career ruined by the assassination), not clips of classical plays. Brando later said, "When Fox couldn't get a top-rate actor like Olivier or me, they settled for ... a third -rate performer with even worse skin."
At Edwin's opening of Hamlet in London's Prince Charles Theatre there is a lady in a red hat. She must have liked his performance, because she's in the audience for every subsequent performance.