Letter to Larry
20 November 2011 Last updated at 12:20 GMT
Kenneth Branagh has told Andrew Marr how he once wrote to Laurence Olivier as a young actor. Olivier wrote back and advised him to "have a bash and hope for the best".
Branagh plays Laurence Olivier in his new film My Week With Marilyn alongside Michelle Williams. It tells the story of what went on behind the scenes, when Olivier was making a comic film The Prince and the Showgirl, in 1956, with Marilyn Monroe.
The actor told Andrew Marr how he would listen to recordings of Laurence Olivier reading the Bible every morning, while he was having his prosthetic chin attached, to learn his way of speaking.