Hercule Poirot met his lifelong friend, Captain Arthur Hastings, and solved the first of his cases to be published, "The Mysterious Affair at Styles". It is clear that Hastings and Poirot are already friends when they meet in Chapter 2 of the novel, as Hastings tells Cynthia that he has not seen him for "some years". Particulars such as the date of 1916 for the case and that Hastings had met Poirot in Belgium, are given in "Curtain: Poirot's Last Case", Chapter 1. After that case, Poirot apparently came to the attention of the British secret service and undertook cases for the
Hercule Poirot in literature canon by most fans and biographers. This would render everything else (plays, movies, television adaptations, etc.) as an adaptation, or secondary material. A contradiction between the novels can be resolved, in most cases, by going with the novel that was published first. An example of this would be the ongoing controversy over Poirot's age. Taken at face value it appears that Poirot was over 125 years old when he died. Though the majority of the Hercule Poirot novels are set between World War I and World War II, the later novels then set him in the 1960s (which is contemporary