In Paris in 1859, Gautier became keeper of the imperial archives and of the archives of the département of Haute-Marne. In 1871 he became professor of paleography at the École des Chartres, the school in which he had been educated (1852–55). He was elected a member of the Académie des Inscriptions et Belles-Lettres in 1887 and became chief of the historical section of the national archives in 1893. His works include Les Épopées françaises, 3 vol. (1886–88; “The French Epics,” 2nd ed., 5 vol., 1878–97, with a bibliography of chansons de geste).