Frances Mossiker, writer, was born on April 9, 1906, in Dallas, Texas, the daughter of Elihu and Evelyn (Beekman) Sanger. She was raised in wealth derived from the family business, the prosperous manufacturing and retail establishment Sanger Brothers. She frequently visited her mother's family in France and became fluent in French and German. She attended the Hockaday School and Forest Avenue High School and attempted to join the circus at fifteen but was stopped by her grandfather, Alexander Sanger. She enrolled at Smith College but was prevented by college policy from remaining a student after she eloped with Frank Beaston, an actor, about 1922. She graduated Phi Beta Kappa from Barnard in 1927, did graduate work at the Sorbonne in Paris, then moved to Detroit and to Hollywood with her husband; the marriage ended in divorce about 1929, and she returned to Dallas.
Frances Beaston worked as a radio commentator in Dallas and Fort Worth. She married businessman Jacob Mossiker on October 15, 1935. The couple traveled widely and lived comfortably. They had no children. When she was in her early fifties, while recovering from a radical mastectomy, Frances Mossiker began to research the disappearance of a diamond necklace in eighteenth-century France. Through family and friends she gained access to primary documents in France, and the result was the nonfiction mystery The Queen's Necklace, published in 1961. The book won the Carr P. Collins award from the Texas Institute of Letters. Mossiker was the first woman to win the prize. She followed this book with the Literary Guild selection Napoleon and Josephine: The Biography of a Marriage (1964), The Affair of the Poisons (1969), More Than a Queen: The Story of Josephine Bonaparte (1971), Pocahontas: The Life and Legend (1976), and Madame de Sevigne: A Life and Letters (1983). She donated her papers to the Harry Ransom Humanities Research Center at the University of Texas at Austin, to Boston University, and to Smith College. She died on May 12, 1985, in Dallas and was entombed at Hillcrest Mausoleum.