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, charting a profound shift in the social structures of medieval society around the year 1000.
If the King Louis XII were to die without producing a male heir, Charles of the House of Habsburg would receive as dowry the Duchy of Milan, Genoa and its dependencies, the Duchy of Brittany, the counties of Asti and Blois, the Duchy of Burgundy, the Viceroyalty of Auxonne, Auxerrois, Mâconnais and Bar-sur-Seine.