Christie’s version of Englishness is “there to be played with, rather than grimly realistic,” says the University of Hull English lecturer Sabine Vanacker. As with other classic crime fiction, her settings and characteristics take some artistic licence and even have elements of caricature. In reality, of course, not every British village has a kindly vicar, a blowhard colonel, a brittle lawyer, and a twinkling doctor – or indeed a preponderance of murderers. There’s also a surprising lack of pubs in her stories.

But not all of Christie’s version of Englishness is fanciful.

“The self-deprecation to me is what really comes through,” says Donovan. He sees something particularly English about the way Christie, either through her narration or her characters, uses dry wit, often gallows humour. In the short story Triangle at Rhodes, for example, she writes of one Englishwoman abroad:

“Unlike most English people, she was capable of speaking to strangers on sight instead of allowing four days to a week to elapse before making the first cautious advance as is the customary British habit.”

This kind of humour was very much part of the author’s personality, says Janet Morgan, (author of an official biography of Agatha Christie). Morgan explains that while Christie had strong beliefs about good and evil. “She was a very humorous person… She was amused by life, and by human beings, and by how they behaved.”