Mary Wollstonecraft Shelley, english Romantic novelist, biographer and editor, best known as the writer of 'Frankenstein or the modern Prometheus' (1818). Mary Shelley was 21 when the book was published; she started to write it when she was 18. The story deals with an ambitious young scientist. He creates life but then rejects his creation, a monster. The story of Frankenstein's monster has inspired over 50 films..