Agatha Christie (15 September 1890 – 12 January 1976) was an English author known for her detective novels, particularly those revolving around fictional detectives Hercule Poirot and Miss Marple. She is widely regarded as one of the greatest writers, particularly in the mystery genre. A writer has been called the 'Queen of Crime'. She is the best-selling fiction writer of all time, her novels having sold more than two billion copies. Her first novels published since 1920 till 1929 are in public domain now under US copyright law.