In 1920, the figure of Hercule Poirot arrived, fully formed – from the top of his egg-shaped head to the tip of his toes – when Agatha Christie published her first detective novel, The Mysterious Affair at Styles. She introduced her detective in the words of an admiring narrator who was to function as a kind of Dr Watson to her Great Detective. Poirot, we are told ‘was an extraordinary looking little man, hardly more than five feet four inches, but he carried himself with great dignity’. His famous moustache was at that stage simply ‘stiff and military’, but his considerable ego was already established. ‘No one but Hercule Poirot would have attempted such a thing!’ he proclaims, in the final pages, as he explains how he orchestrated his unmasking of the guilty parties.