Conversation so far:
When did Mortimer start John Mortimer's legal career?
Mortimer was called to the Bar (Inner Temple) in 1948, at the age of 25.
What firm did he work for?
CANNOTANSWER.
What type of law did he practice?
His early career consisted of testamentary and divorce work.

Question: Did that change later in his career?
Self-contained rewrite: Did John Mortimer change career later?