Although not as well-known as Mary Wollstonecraft (1759–1797), her friend and fellow women’s rights advocate, London native Mary Hayes (1760–1843) was her equal in passion for obtaining justice for women. Hayes came from a family of Rational Dissenters, a group of Christians who followed the practices of the Church of England in principle but rejected certain aspects of that faith, including its reliance on unquestioning obedience to authority. Hays was an autodidact; she educated herself through correspondence with a fellow Dissenter and through contact with some of the leading Dissenters of the day. These included the scientist Joseph Priestley and Theophilus Lindsey, the founder of the Unitarian sect. She wrote a tract in defense of Unitarianism and became famous as the author of novels that caused scandals because of their forthright depiction of feminist ideals, including Memoirs of Emma Courtney (1796) and The Victim of Prejudice (1799). Perhaps her best-known work is Female Biography (1803), one of the earliest works of women’s history.