Margaret Cavendish, then Lucas, was born in 1623 to a wealthy family. In 1644, as England descended into civil war, she joined the court of the formidable Queen Henrietta Maria at Oxford, before following the court into exile in France. It was there that she met her much older lifelong partner, William Cavendish, Marquess of Newcastle-upon-Tyne. Cavendish was a revolutionary writer. At a time when literature was dominated by men, she wrote passionately on gender, science and philosophy, defied convention by publishing under her own name, and advocated for women in work that predates the feminist movement. In 1666, she published The Blazing World, a brilliant, trail-blazing proto-novel thought to be one of the earliest works of science fiction. But her legacy divides opinion. And history has largely forgotten her. In Pure Wit, Francesca Peacock shines a spotlight on the fascinating, pioneering, yet often complex and controversial life of Margaret Cavendish.