Shelley, Mary: - Mary Shelley was only eighteen when Lord Byron challenged a group of friends to write the best horror story. She fleshed out her original and this was accepted for publication when she was just twenty. Shelley wrote several novels after Frankenstein but none of them has stood the test of time, although in her lifetime she was taken seriously as a writer, especially of biographies. She died in 1851, thirty years after the tragic early death of her husband Percy.