Conversation so far:
When did John Mortimer start his legal career?
John Mortimer was called to the Bar (Inner Temple) in 1948.
What firm did John Mortimer work for?
John Mortimer was called to the Bar (Inner Temple).
What type of law did John Mortimer practice?
John Mortimer's early career consisted of testamentary and divorce work.
Did John Mortimer's legal work change later in his career?
On taking silk in 1966, John Mortimer began to undertake work in criminal law.
What does taking silk mean?
Appointment as Queen's Counsel is known informally as taking silk.
Did John Mortimer work on any major cases?
John Mortimer did represent publishers John Calder and Marion Boyars.

Question: When was this case?
Self-contained rewrite: When was the Calder and Boyars case that John Mortimer represented?