Mary’s greatest work is Frankenstein (1818), which she began when she
was nineteen years old, after having spent the summer at Byron’s house
in Geneva with her husband. As the group sat around the fire one rainy evening, Byron suggested that each should write their own ghost story, and from this competition Frankenstein was born; the novel has never, since its first publication, gone out of print. She also wrote five other major novels, including Valperga and The Last Man, biographies, essays and short stories.