Frances Gies, née Carney, was born in Ann Arbor, Michigan, a daughter of Prof. Robert John Carney and his wife Frances Gibson Carney. She graduated Phi Beta Kappa from the University of Michigan in 1937 with a B.A. degree, and in 1938 earned an M.A. in English and a teacher’s certificate. In 1940, after teaching high school English in Caro, Michigan, for two years, she went to New York City. There she married Joseph Gies, a writer who also hailed from Ann Arbor, with whom she had three children. Frances worked as a reader for the story department of 20th Century-Fox, while her husband was an editor at This Week Magazine, the Sunday magazine of the New York Herald Tribune. During World War II, he served in the U.S. Army in France and Germany. After the war, they began a new career as historians and writers collaborating on a dozen books about life in the Middle Ages, including Life in a Medieval City, Life in a Medieval Castle, Life in a Medieval Village, and Cathedral, Forge, and Waterwheel. She also wrote three individual works, Women in the Middle Ages, Joan of Arc: The Legend and the Reality, and The Knight in History.