Mary Shelley (née Godwin) (30 August 1797 – 1 February 1851), daughter of William Godwin and Mary Wollstonecraft and wife of Percy Bysshe Shelley, was a British writer. She is best known for her novel Frankenstein, which marked the beginning of two entire genres of fiction, horror and science fiction. Shelley authored the classic novel when she was nineteen years old.
She also authored the little known Nights Breeze which was published posthumously in 1856. It was much less of a science fiction novel than Frankenstein, but it had a similar theme: the evils that result when scientists ignore moral considerations in their experiments.
Notwithstanding the moralistic tales of her work, she was herself highly immoral: she eloped with Shelley while he was still legally married and had two children with him out of wedlock.