When actor Richard Harris, who played Hogwarts headmaster Albus Dumbledore in the first two Harry Potter films, died in 2002, the filmmakers needed to find a replacement fast for the third installment, Harry Potter and the Prisoner of Azkaban. Ian McKellen told the BBC that the filmmakers approached him about being Hogwarts’ headmaster, but he had to decline. It wasn’t that he was busy playing Gandalf in Lord of the Rings or that he didn’t like Potter — McKellen is just a stand-up guy who knew that Harris wasn’t a fan of his work. Once, McKellen said, Harris called him “technically brilliant, but passionless.” Telling the story to the BBC, McKellen said he wasn’t mad at Harris’s shade, he just said he couldn’t take the role with a clear conscience. “When they called me up and said would I be interested in being in the Harry Potter films, they wouldn’t say what part but I worked out what they were thinking,” McKellen explained. “I couldn’t take over the part from an actor who I know disapproved of me.” And so that’s how we got stuck with Michael Gambon.