What is the name of Agatha Christie’s first published novel, featuring Hercule Poirot?

Agatha Christie’s first published novel, featuring Hercule Poirot, is The Mysterious Affair at Styles. It introduced Poirot, Captain Arthur Hastings, and Inspector Japp to readers in 1920.

Christie wrote the novel during the First World War, and its country-house setting established several features associated with her later mysteries: a confined group of suspects, concealed motives, misleading clues, and a final explanation by the detective. Poirot’s Belgian nationality also reflects Christie’s wartime experience working with Belgian refugees in England.

The novel was initially rejected by several publishers before John Lane’s Bodley Head accepted it. Its publication began Christie’s long career as one of the world’s best-known crime writers. The title refers to Styles Court, the Essex manor where the central murder occurs.

It is sometimes confused with The Secret Adversary, Christie’s second published novel, which introduced Tommy and Tuppence rather than Poirot.