Agatha Christie was an award-winning English writer known for her 66 detective novels and 14 short story collections, particularly those revolving around fictional detectives Hercule Poirot and Miss Marple. She also wrote romances under the pseudonym Mary Westmacott. In 1971, she was appointed a Dame Commander of the Order of the British Empire (DBE) to honor her many contributions to literature. Guinness World Records lists Christie as the best-selling novelist of all time. Her novels have sold roughly 2 billion copies, coming in third in the rankings of the world's most-widely published books, second only to Shakespeare and the Bible. 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.