Agatha Christie was an English writer known for her detective novels and short stories. Some of her most famous works include Murder on the Orient Express, Death on the Nile, and And Then There Were None. She created two iconic sleuths - the Belgian detective Hercule Poirot and elderly spinster Miss Marple. Poirot appeared in 33 novels while Miss Marple featured in 12 novels and 20 short stories between them. Christie is considered the best-selling novelist of all time with over 2 billion copies of her work sold.