The influential British historian known for his contributions to the study of medieval society is Marc Bloch. His work, particularly in the field of historical sociology, emphasized the importance of social structures and cultural context in understanding history. Bloch co-founded the Annales School, which advocated for a more multidisciplinary approach to history, focusing on long-term social and economic factors. His insights paved the way for modern historiography and enriched the study of medieval history.