Dame Agatha Mary Clarissa Christie, Lady Mallowan, was an English author known for her 66 detective novels and 14 short story collections, particularly those revolving around the fictional detectives Hercule Poirot and Miss Marple.

Christie is widely regarded as one of the greatest writers in the mystery genre. A seminal figure of the "Golden Age of Detective Fiction," she has been dubbed the "Queen of Crime." Her play, "The Mousetrap," holds the record for the world's longest-running play.

Born in Torquay, Devon, Christie grew up in a wealthy, upper-middle-class family and was largely home-schooled. Despite initial setbacks with six rejections, her career took off in 1920 with the publication of "The Mysterious Affair at Styles."

She was married twice, first to Archibald Christie and later to archaeologist Max Mallowan. Her travels to the Middle East with Mallowan influenced many of her works. Christie's expertise in poisons, gained during her work in hospital dispensaries during the world wars, frequently featured in her stories.

According to UNESCO, she remains the most-translated individual author. Her novel "And Then There Were None" is one of the best-selling books of all time. In 1971, she was made a Dame Commander of the Order of the British Empire (DBE) for her contributions to literature.

Christie's works have been adapted for television, radio, and film, securing her place as the best-selling fiction writer of all time, with over two billion copies sold worldwide.