In contradistinction to Bloch, the Belgian historian François-Louis Ganshof defined feudalism from a narrow legal and military perspective, arguing that feudal relationships existed only within the medieval nobility itself. Ganshof articulated this concept in "Qu'est-ce que la féodalité?" ("What is feudalism?", 1944; translated in English as "Feudalism"). His classic definition of feudalism is widely accepted today among medieval scholars, though questioned both by those who view the concept in wider terms and by those who find insufficient uniformity in noble exchanges to support such a model. Although he was never formally a student in the circle of scholars around Marc Bloch and Lucien Febvre that came to be known as the Annales School, Georges Duby was an exponent of the "Annaliste" tradition. In 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"), and working from the extensive documentary sources surviving from the Burgundian monastery of Cluny, as well as the dioceses of Mâcon and Dijon, Duby excavated the complex social and economic relationships among the individuals and institutions of the Mâconnais region and charted a profound shift in the social structures of medieval society around the year 1000. He argued that in early 11th century, governing institutions—particularly comital courts established under the Carolingian monarchy—that had represented public justice and order in Burgundy during the 9th and 10th centuries receded and gave way to a new feudal order wherein independent aristocratic knights wielded power over peasant communities through strong-arm tactics and threats of violence. In 1939 the Austrian historian subordinated the feudal state as secondary to his concept of a persons association state (""), understanding it in contrast to the territorial state. This form of statehood, identified with the Holy Roman Empire, is described as the most complete form of medieval rule, completing conventional feudal structure of lordship and vassalage with the personal association between the nobility. But the applicability of this concept to cases outside of the Holy Roman Empire has been questioned, as by Susan Reynolds. The concept has also been questioned and superseded in German histography because of its bias and reductionism towards legitimating the Führerprinzip. In 1974, the American historian Elizabeth A. R. Brown rejected the label "feudalism" as an anachronism that imparts a false sense of uniformity to the concept.