“One doesn’t recognise the really important moments in one’s life until it’s too late,” wrote Agatha Christie in her 1935 novel Peril at End House. Even Christie herself may have struggled to narrow down the most significant moments in her own life – perhaps it would be the publication of her first novel, The Mysterious Affair at Styles, in 1920, or maybe it would be a trip on the Orient Express which went on to inspire one of her greatest works? Or, could it be her job as a nurse during the First World War, or a damehood granted by the late Queen Elizabeth II in 1971. Suffice to say, one of Britain’s most brilliant storytellers certainly had a storied life. 

50 years on from her death, her wide-ranging portfolio – featuring beloved characters like Belgian detective Hercule Poirot and English investigator Miss Marple, alongside mysteries And Then There Were None, The Murder of Roger Ackroyd, and A Murder is Announced – has captivated readers for more than a century. She remains the best-selling novelist of all time, having sold more than a billion copies in the English language and a further billion in translation – coming second only across all genres to the Bible and Shakespeare. 

Christie’s influence endures partly due to her work’s seamless transition to screen and stage. She turned her hand to plays – The Mousetrap is famous for being the longest-running show in London’s West End, opening in 1952 and still playing today at St Martin’s Theatre – but it is the 1974 adaptation of Murder on the Orient Express that truly popularised her work in Hollywood. 

Agatha Christie in 1959. Image: Alamy

Agatha Christie’s Seven Dials lands on Netflix this week. Image: Netflix

Add to that the 24-year-long Poirot television series, starring a perfectly-moustached David Suchet, and all the chronicles of Miss Marple that have been adapted for screen since the 1990s, Christie’s influence is nothing short of remarkable. It shows no signs of waning either: this week Agatha Christie’s Seven Dials lands on Netflix, starring Mia McKenna Bruce, Helen Bonham-Carter and Martin Freeman. 

Christie, herself, however may have been shocked by her starry trajectory and long-term legacy, especially given her first six novels were rejected by publishers. “Initially, she wrote for pleasure,” explains Gill Plain, professor of English at the University of St Andrews and the author of Agatha Christie: A Very Short Introduction, which was published last year. “She enjoyed a happy Victorian childhood, albeit one where she spent a lot of time on her own, making up imaginary friends.” 

Born in Torquay in 1890 as one of three children, Christie described her childhood as “very happy” until her father died when she was 11. With her older sister married and her older brother serving in the military overseas, Christie lived alone with her mother for the duration of her adolescence and often had her head in books by Edward Lear, Lewis Carroll and Charles Dickens. Plain says: “She would make up stories for friends and family, and when she was older – coming out in Cairo – she tried her hand at a novel which she called Snow Upon the Desert.

“It was a hobby, an entertainment, but she tried to get it published – unsuccessfully. Her first detective novel, The Mysterious Affair at Styles, was drafted during the First World War. Christie became a VAD (voluntary aid detachment) nurse, and ended up working in the hospital dispensary, surrounded by poisons and drugs. This would be the first Poirot novel. It didn’t find a publisher until 1920, and then on not very good terms – but at the time she didn’t mind because (so her autobiography says) she was writing for fun.”

Initially, Christie didn’t publish to make money – something which now seems unfathomable given, at the time of her death in 1976, her net worth was reported to be in the region of $600 million (just over $5.3 billion in today’s money). “It was exciting to sell a story, and she enjoyed the money it brought her. Indeed, in her autobiography, she credits The Man in the Brown Suit (1924) for paying for her first car. Later in life, after her divorce, she had to take her writing much more seriously – and she became a consummate professional.”

After finishing boarding school in Paris, where she was training to become a professional pianist and vocalist, 19-year-old Christie took her then ailing mother to the Egyptian capital of Cairo to benefit from the warmer climate. It was her first real taste of overseas travel which, throughout her life, became a constant source of inspiration. Plain says: “As a nine-year-old girl, she lived in France for a year [and then] her coming out season was in Cairo, she sailed round a fair bit of the world on a British Empire exhibition mission in 1924, and she accompanied her second husband, the archaeologist Max Mallowan, on his digs in Iraq and Syria. 

“These places feature in the background of her novels, but she seems to most enjoy writing about the journey – the curious transition space of travel. Lots of characters out of place, or thrown together into an uncomfortable temporary community. The journey is a space within which extraordinary things happen. She sets crimes on trains and ships, even on aeroplanes.”

Her cultural influence can still be felt in the world of travel. Case in point, luxury tour operator Original Travel has reported the Steam Ship Sudan – the Nile steamship on which Christie sailed and the inspiration for Death on the Nile – and specifically its Agatha Christie cabin, is more in demand than ever, with fans of the Queen of Crime booking it years in advance. 

Elsewhere, Christie’s renowned 1934 novel, Murder on the Orient Express, takes place on the Simplon Orient Express and was inspired by her many journeys aboard the train – but notably nods to an occasion in 1931 when she was travelling alone and the train stopped in the middle of the night as the line had flooded during a storm. “She certainly did wonders for the Orient Express – which is funny as, [she mentions in] the autobiography that she got severely bitten by bed bugs when she travelled on it! But she loved to travel,” adds Plain. 

So, why were her stories so successful – and readable? Her prose, filled with puzzles, is a glaringly obvious factor. “Her books are easy and pleasurable to read (this might also contribute to their success in translation),” says Plain. “They are also good examples of a genre that has never really gone out of fashion – the clue-puzzle detective story. You can see the basic formula at work in shows from Midsomer Murders to the CSI franchise, and now in shows like Death in Paradise. 

“Christie was exceptionally good at generating the sort of complex plotting these stories need – even if she used the same technique multiple times (impersonation, for example), she knew how to disguise her intentions and do it differently – but she was also very good at creating accessible characters.”

Hercule Poirot and Miss Marple are some of the most famous literary characters in the world – and, as Plain explains, there’s a reason they have stuck in so many minds. “Christie is often dismissed as writing cardboard characters – and she does rely on stereotypes to a certain extent – but she has real skill in deftly sketching a familiar type that her readers can recognise. It doesn’t matter if her books are set in the 1920s or the 1950s, we all still know what a pompous self-made man is like, or a put-upon housewife, and can imagine one from our own experience. 

David Suchet as Hercule Poirot on the set of The Chocolate Box in 1992 at Grand Place, Brussels. Image: Shutterstock/Capture PB

Agatha Christie aboard the SS Sudan

“Beyond these types, she also succeeded in creating two brilliant examples of the underestimated outsider detective: Hercule Poirot, the comical foreigner, and Miss Marple, the village spinster. There is huge pleasure in watching underestimated figures turn the tables. Yet neither Poirot nor Marple are superhero figures, nor do they have specialist knowledge. They work through everyday methods – so, the reader of these books does have a chance of working out what is going on.”

Plain also says that Christie’s choice for her iconic characters to look and act a certain way was very much intentional. “Poirot is the classic outsider figure: he is a foreigner – but Christie was clever in making him Belgian, as Belgium is a small country, associated, especially after the First World War, with vulnerability – rather than, for example, France. If she’d made Poirot French, there would have been a whole history of Anglo-French relations and prejudices complicating his appearances. 

“He is also the antithesis of what English masculinity is supposed to be, and the critic Alison Light has observed that Christie enjoys making fun of conventional modes of British imperial heroism. Poirot is described as small, with an egg-shaped head and ‘suspiciously black hair’; he is absurdly proud of his moustache, precise and vain about his appearance, and absolutely convinced of his own brilliance. He is never modest. 

“Miss Marple is different. She’s an outsider because she is an elderly spinster – two characteristics seldom forgiven in women – but she’s also an insider. She has lived in St Mary Mead for an eternity and knows everything about everybody. She is part of the community, unlike Poirot who always comes in from outside. She is also conveniently well-connected, knowing a few chief constables – but the way she investigates is open to everyone. She thinks the worst, and is usually right! 

“The characters work across the generations because they are sufficiently detailed to be special and memorable – they have catchphrases and mannerisms – but not so detailed that they get rooted in a specific time or place. Like Sherlock Holmes or James Bond, each of them can be reinvented anew for new generations. Hence the sheer number of adaptations…”

Iconic, of course – however, Plain says Christie can’t be credited with changing the murder mystery genre irrevocably, no matter how much she did, and still does, for it. “You can’t attribute that to one writer. She became a bestseller and a phenomenon, and she has become a shorthand for a type of writing, but the murder mystery genre is too big and multifaceted to be beholden only to Christie. There were lots of writers producing ‘clue-puzzle’ mysteries, and there were equally important changes generated by ‘hardboiled’ writers, like Raymond Chandler and Dashiell Hammett. 

“Christie also wrote a more diverse range of novels than is usually acknowledged – for example, she wrote quite a few thrillers, often with plucky female heroes, and her crime novels changed over the years in terms of structure and preoccupation. One of the most popular murder formats today is the police procedural, and that is something that Christie never wrote!”

Christie’s enduring influence, 50 years on from her death and 53 years since she last put pen to paper, continues to shape contemporary mysteries. Think of modern-day crime writers like Richard Osman, or characters like Benoit Blanc, played by Daniel Craig in the Knives Out series, and it isn’t hard to trace a line directly back to Christie. Plain confirms: “The Thursday Murder Club nods to the first stories to feature Miss Marple, where she was part of the ‘Tuesday Night Club’ – a group of friends examining puzzles and unsolved mysteries, where Miss Marple always finds the solution. 

“Similarly, the Knives Out films owe a debt to Christie in the formula they adopt and the type of detection they employ – and in their combination of the serious and the absurd. Benoit Blanc is a Christiesque detective. But fabulous as these are, I think they complement Christie in both senses of the word, they don’t supplant her.”

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