Margaret Lucas Cavendish, Duchess of Newcastle-upon-Tyne (1623 – 15 December 1673) was an English philosopher, poet, scientist, fiction writer and playwright. Her husband William Cavendish, 1st Duke of Newcastle-upon-Tyne, was Royalist commander in Northern England during the First English Civil War and in 1644 went into self-imposed exile in France. Margaret accompanied him, and remained abroad until the Stuart Restoration in 1660. She wrote in her own name in a period when most women writers remained anonymous.