Hercule Poirot is a fictional Belgian detective created by Agatha Christie

Agatha Christie

Dame Agatha Christie DBE was a British crime writer of novels, short stories, and plays. She also wrote romances under the name Mary Westmacott, but she is best remembered for her 66 detective novels and 14 short story collections , and her successful West End plays.According to...

. Along with Miss Marple

Miss Marple

Jane Marple, usually referred to as Miss Marple, is a fictional character appearing in twelve of Agatha Christie's crime novels and in twenty short stories. Miss Marple is an elderly spinster who lives in the village of St. Mary Mead and acts as an amateur detective. She is one of the most famous...

, Poirot is one of Christie's most famous and long-lived characters, appearing in 33 novels and 51 short stories published between 1920 and 1975 and set in the same era.

Poirot has been portrayed on radio, on screen, for films and television, by various actors, including John Moffatt, Albert Finney

Albert Finney

Albert Finney is an English actor. He achieved prominence in films in the early 1960s, and has maintained a successful career in theatre, film and television....

, Sir Peter Ustinov

Peter Ustinov

Peter Alexander Ustinov CBE was an English actor, writer and dramatist. He was also renowned as a filmmaker, theatre and opera director, stage designer, author, screenwriter, comedian, humourist, newspaper and magazine columnist, radio broadcaster and television presenter...

, Sir Ian Holm

Ian Holm

Sir Ian Holm, CBE is an English actor known for his stage work and for many film roles. He received the 1967 Tony Award for Best Featured Actor for his performance as Lenny in The Homecoming and the 1998 Laurence Olivier Award for Best Actor for his performance in the title role of King Lear...

, Tony Randall

Tony Randall

Tony Randall was a U.S. actor, comic, producer and director.-Early years:Randall was born Arthur Leonard Rosenberg to a Jewish family in Tulsa, Oklahoma, the son of Julia and Mogscha Rosenberg, an art and antiques dealer...

, Alfred Molina

Alfred Molina

Alfred Molina is a British-born American actor. He first came to public attention in the UK for his supporting role in the 1987 film Prick Up Your Ears...

 and David Suchet

David Suchet

David Suchet, CBE, is an English actor, known for his work on British television. He is recognised for his RTS- and BPG award-winning performance as Augustus Melmotte in the 2001 British TV mini-drama The Way We Live Now, alongside Matthew Macfadyen and Paloma Baeza, and a 1991 British Academy...

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His name was derived from two other fictional detectives of the time: Marie Belloc Lowndes' Hercule Popeau and Frank Howel Evans' Monsieur Poirot, a retired Belgian police officer living in London.
Hercule Poirot's initials replicate that of the sauce which he happens to like, HP Brown Sauce, as he comments in Elephants Can Remember

Elephants Can Remember

Elephants Can Remember is a work of detective fiction by Agatha Christie, first published in the UK by the Collins Crime Club in November 1972 and in the US by Dodd, Mead and Company later in the same year. The UK edition retailed for £1.60 and the US edition at $6.95.It features her Belgian...

: "Ah yes, that is correct my initials do appear to be the same as such a fine delicacy, a good English creation".
A more obvious influence on the early Poirot stories is that of Arthur Conan Doyle

Arthur Conan Doyle

Sir Arthur Ignatius Conan Doyle DL was a Scottish physician and writer, most noted for his stories about the detective Sherlock Holmes, generally considered a milestone in the field of crime fiction, and for the adventures of Professor Challenger...

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