Agatha Christie's first novel "The Mysterious Affair at Styles" was published in 1920 and introduced this long-running character detective who appeared in 30 of Christie's novels and 50 short stories. Can you name him?

Hercule Poirot is correct - Agatha Christie's first published novel The Mysterious Affair at Styles (1920) introduced the Belgian detective who became her most famous recurring character. Roger Ackroyd is a murder victim in a later Poirot novel, Arthur Hastings is Poirot's recurring partner, and Phillip Marlowe was created by Raymond Chandler.