Nicola Chalton has written and contributed to several non-fiction books, including a series on the history of science and philosophy (Philosophers: They Changed the World and Scientists: They Changed the World). She runs a small publishing business in North Yorkshire with her husband. Meredith MacArdle is a writer and editor who lives in London. She is the co-author of The Twentieth Century in Bite-sized Chunks and the author of The Timeline History of China and The Timeline History of the Middle Ages, among other books.