During her first marriage, Agatha published six novels, a collection of short stories, and a number of short stories in magazines. Her first novel, The Mysterious Affair at Styles, came out in 1920. During the Second World War, she worked as a pharmacy assistant at University College Hospital, London, acquiring a good knowledge of poisons which feature in many of her novels. During the First World War, she worked at a hospital as a nurse later working at a hospital pharmacy, a job that influenced her work, as many of the murders in her books are carried out with poison. The Millers had two other children: Margaret Frary Miller (1879–1950), called Madge, who was eleven years Agatha's senior, and Louis Montant Miller (1880–1929), called Monty, ten years older than Agatha.īefore marrying and starting a family in London, she had served in a Devon hospital during the First World War, tending to troops coming back from the trenches. The youngest of three children of the Miller family. She atuhored The Mousetrap, the longest-running play in the history of modern theater. Of the most enduring figures in crime literature, she created Hercule Poirot and Miss Jane Marple. According to Index Translationum, people translated her works into 103 languages at least, the most for an individual author. Her books sold more than a billion copies in the English language and a billion in translation. This best-selling author of all time wrote 66 crime novels and story collections, fourteen plays, and six novels under a pseudonym in romance. More than seventy detective novels of British writer Dame Agatha Mary Clarissa Christie include The Murder of Roger Ackroyd (1926), and And Then There Were None (1939) she also wrote plays, including The Mousetrap (1952).

Agatha Christie also wrote romance novels under the pseudonym Mary Westmacott, and was occasionally published under the name Agatha Christie Mallowan.

Poirot investigates stories