Mary Shelley was brought up by her father in a house filled with radical thinkers, poets, philosophers and writers of the day. Aged sixteen, she eloped with Percy Bysshe Shelley, embarking on a relationship that was lived on the move across Britain and Europe. The life story is well-known, but who was the woman who lived it? Published for the 200th anniversary of the publication of Frankenstein, this is a major new work of biography by a prize-winning writer and poet.