Dame Agatha Mary Clarissa Christie, DBE (born Miller; 15 September 1890 – 12 January 1976) was an English crime novelist, short story writer, and playwright. She also wrote six romances under the name Mary Westmacott, but she is best known for the 66 detective novels and 14 short story collections she wrote under her own name, most of which revolve around the investigations of such characters as Hercule Poirot, Miss Jane Marple and Tommy and Tuppence. She also wrote the world's longest-running play, The Mousetrap.Born into a wealthy upper-middle-class family in Torquay, Devon, Christie served in a hospital during the First World War, before marrying and starting a family in London. She was initially unsuccessful at getting her work published; but in 1920 The Bodley Head press published her novel The Mysterious Affair at Styles, featuring the character of Poirot. This launched her literary career.The Guinness Book of World Records lists Christie as the best-selling novelist of all time. Her novels have sold roughly 4 billion copies, and her estate claims that her works come third in the rankings of the world's most-widely published books, behind Shakespeare's works and the Bible. According to Index Translationum, Christie is the most-translated individual author – having been translated into at least 103 languages. And Then There Were None is Christie's best-selling novel with 100 million sales to date, making it the world's best-selling mystery ever, and one of the best-selling books of all time. In 1971, she was made a Dame by Queen Elizabeth II at Buckingham Palace. In 2013, The Murder of Roger Ackroyd was voted the best crime novel ever by 600 fellow writers of the Crime Writers' Association.Christie's stage play The Mousetrap holds the record for the longest initial run: it opened at the Ambassadors Theatre in London on 25 November 1952 and as of 2012 is still running after more than 25,000 performances. In 1955, Christie was the first recipient of the Mystery Writers of America's highest honour, the Grand Master Award, and in the same year Witness for the Prosecution was given an Edgar Award by the MWA for Best Play.Most of her books and short stories have been adapted for television, radio, video games and comics, and more than thirty feature films have been based on her work.