Conversation so far:
When did John Mortimer start writing?
John Mortimer was classified as medically unfit for military service in World War II. He worked for the Crown Film Unit under Laurie Lee, writing scripts.
What type of works did John Mortimer write?
John Mortimer worked for the Crown Film Unit under Laurie Lee, writing scripts for propaganda documentaries.
Did John Mortimer write any novels?
John Mortimer based his first novel, Charade, on his experiences with the Crown Film Unit.

Question: When did he write Charade?
Self-contained rewrite: When did John Mortimer write Charade?