Poirot? Hercule Poirot first appeared in “The Mysterious Affair at Styles”, which was Christie's first published novel, released in the UK in January 1921 when the English author was 30.
He became a mainstay of her work? Poirot went on to appear in 33 novels and more than 50 short stories, as well as in two plays, with Christie said to have found the character “insufferable" by 1930, before going on to say in later years that she found him “bombastic and tiresome”.
However? Along with her other infamous detective, Miss Jane Marple, Hercule and his “little grey cells” - that helped him solve one mystery after another - were astonishingly successful and Christie told her agent in a letter that Poirot would not be retiring “while he is my chief source of income”.