Hercule Poirot first appeared in Agatha Christie’s debut novel, The Mysterious Affair at Styles, published in 1920. A retired Belgian police officer displaced to England as a World War I refugee, Poirot set himself apart from the dominant Sherlock Holmes tradition by privileging psychology and logical reasoning over physical evidence, a method he encapsulated in his recurring invocation of “the little grey cells” (9). The Mysterious Affair at Styles established many of the conventions that would define the series, including a closed circle of suspects, the partnership with Captain Arthur Hastings as narrator and foil, the final-act revelation in which Poirot assembles all parties to unmask the killer, and an intricate puzzle structure built on misdirection and buried motives. That first novel also introduced the tension between Poirot’s cerebral methods and the more conventional investigative approach favored by official police, a dynamic that recurs throughout the series.

Over the following five decades, Christie wrote 33 Poirot novels and more than 50 short stories. Some of her most celebrated works within the series are The Murder of Roger Ackroyd (1926), which scandalized readers with its controversial narrative twist; Murder on the Orient Express (1934), which is famous for its ingenious solution; and Death on the Nile (1937). Poirot became Christie’s most commercially significant creation, though her relationship with the character grew increasingly fraught; she publicly expressed regret at having invented him yet conceded that his immense popularity made him impossible to retire.

Christie concluded the series with Curtain: Poirot’s Last Case, a novel she wrote during World War II and kept sealed in a vault for over 30 years, releasing it only in 1975 as her own health declined. The novel returns Poirot to Styles, the setting of his first case, where he solves a final murder before dying of heart failure. The cultural impact of this event was extraordinary. On August 6, 1975, The New York Times published a front-page obituary for Poirot, making him the only fictional character ever to receive such treatment from the paper (Lask, Thomas, “Hercule Poirot Is Dead; Famed Belgian Detective,” The New York Times, 6 Aug. 1975). Christie herself died five months later in January 1976.

The character’s afterlife in adaptation has been equally significant. Albert Finney received an Academy Award nomination for his portrayal of Poirot in Sidney Lumet’s 1974 film Murder on the Orient Express, and Peter Ustinov subsequently played the detective in six productions beginning with Death on the Nile (1978). The most comprehensive screen adaptation, however, was the ITV television series Agatha Christie’s Poirot (1989–2013), in which David Suchet starred across 70 episodes over 24 years, ultimately adapting every major Poirot work Christie had written. More recently, Kenneth Branagh directed and starred in a cinematic trilogy beginning with Murder on the Orient Express (2017). Collectively, these adaptations have ensured that Poirot remains one of the most recognizable figures in detective fiction, sustaining Christie’s reputation as the bestselling fiction writer of all time.