Charles-Victor Langlois (May 26, 1863, in Rouen – June 25, 1929, in Paris) was a French historian, archivist and paleographer, who specialized in the study of the Middle Ages and was a lecturer at the Sorbonne, where he taught paleography, bibliography, and the history of the Middle Ages. Langlois attended the École Nationale des Chartes and earned a doctorate in history in 1887. He taught at the University of Douai before moving to the Sorbonne. He was director of the National Archives of France from 1913 to 1929. Langlois was a leader in use of the historical method, which taught a scientific form of studying history. His "Manual of Historical Bibliography" was a fundamental manual on how bibliographic methods, which went along with his studies of the historical method. Source: Wikipedia (en)