Conversation so far:
What were some of Agatha Christie's first novels?
Agatha Christie wrote her detective novel, The Mysterious Affair at Styles, featuring Hercule Poirot, a former Belgian police officer noted for his twirly large magnificent moustaches and egg-shaped head.
Was The Mysterious Affair at Styles by Agatha Christie successful?
This first mystery novel by Agatha Christie was well received by reviewers.

Question: Who is Poirot?
Self-contained rewrite: Who is Hercule Poirot?