Sarah Jennings was the daughter of Richard Jennings, a Member of Parliament, and his wife Frances Thornhurst. In 1673, she went to court as a maid-of-honor to Mary of Modena, the second wife of James, Duke of York (later King James II) and became a close friend of James's younger daughter Princess Anne (later Queen Anne I). The two women grew so close that rank and title meant nothing between them -- they referred to each other by nicknames, Anne being Mrs. Morley and Sarah Mrs. Freeman. Sarah was tall, beautiful, and graceful and Princess Anne adored her. In 1678, Sarah married John Churchill, 10 years her senior, against the wishes of both families, and the couple had seven children. During the Glorious Revolution of 1688, the Churchills switched their allegiance from King James to William and Mary, who supplanted James on the throne. After Anne succeeded to the throne in 1702, she made Sarah and her husband Duke and Duchess of Marlborough. Sarah completely controlled and dominated the queen's household, holding the highest positions as Mistress of the Robes and Keeper of the Privy Purse. However, her imperious ways eventually eroded her friendship with the queen. Queen Anne broke with the couple in 1711, when Sarah had been supplanted in the queen’s affections by Abigail Masham, a relative. The couple went abroad and returned to England after Queen Anne's death. Sarah spent her final years quarrelling with relatives and supervising the completion of Blenheim Palace. Her memoirs, published in 1742, represented the first truly political autobiography written by a woman in English.