 He remained attached to the Collège until his retirement in 1991.He was elected to the Académie française in 1987.Although Duby authored dozens of books, articles and reviews during his prolific career—for academic as well as popular audiences—his reputation and legacy as a scholar will always be attached to his first monograph, a published version of his 1952 doctoral thesis entitled "La société aux XIe et XIIe siècles dans la région mâconnaise" ("Society in the 11th and 12th centuries in the Mâconnais region").