René de La Croix de Castries, marquis de Castries, the son of an ancient French noble family, used the courtesy title duc de Castries. He was born and grew up in the Gard or Gardon, a region in southern France. He studied at the Sainte-Genevieve School in Versailles before entering the École libre des sciences politiques ("Sciences Po"), one of the great universities, from which he graduated in 1932. He intended a career in diplomacy, but abandoned this idea after marriage in 1934 to Monique de Cassagne, with whom he had three children. In 1935, he bought the Château de Castries near Montpellier and began to restore the building and cultivate the vineyards that surround it. He was called up by the French Army at the start of World War II and sent to Lebanon. Returning to Castries in 1940, he was appointed mayor of the village in 1941, a position he held until 1950. He began work on the family archives and wrote several novels -- his first book, Mademoiselle de Méthamis (1945), won the Prix Balzac. In 1951, he moved to Paris and began writing works of biography and history. He was elected to the Académie française in 1972. He gave the Institut de France his château in 1985. His last book, published posthumously, was devoted to the life of the salonniere Claudine de Tencin, known as Madame de Tencin.