Conversation so far:
Where did Patrick O'Brian spend his childhood?
Patrick O'Brian had sporadic schooling and long intervals at home in Lewes, East Sussex.
What is the name of Patrick O'Brian's first wife?
Patrick O'Brian was living in London, where he married his first wife, Elizabeth Jones, in 1936.
Aside from writing, what other job did Patrick O'Brian do in his early career?
Patrick O'Brian worked as an ambulance driver, and he stated that he worked in intelligence.
Did Patrick O'Brian serve in the military?
When did Patrick O'Brian first publish his first novel, Caesar: The Life Story of a Panda Leopard?
Patrick O'Brian's first novel, Caesar: The Life Story of a Panda-Leopard, was written at the age of 12 and published three years later in 1930.
Where was Patrick O'Brian born?
Patrick O'Brian was born Richard Patrick Russ, in Chalfont St. Peter, Buckinghamshire.

Question: At what age did he published his first work?
Self-contained rewrite: At what age did Patrick O'Brian publish his first work, Caesar: The Life Story of a Panda Leopard?