Iron metallurgy on the Armorican Massif in medieval and modern times: between ruptures, metallurgical innovations and traditions

The Armorican Massif is a region rich in iron ores of different nature and size. Their exploitation started as early as the beginning of the Iron Age and continued until the end of the twentieth century. A multi-disciplinary approach has been used, integrating the study of historical sources, field investigations, excavation of metallurgical workshops and archaeometric investigations on slags. It clearly shows that iron production for the medieval period, which has been until now highly underestimated, was in fact very significant. However, production evolved with time in terms of technology and social organisation, starting from a diffuse production during the Early Middle Ages to a probably more massive one during High and Late Middle Ages. This long-lasting exploitation has deeply modified the landscape, with significant topographic changes and intense deforestation during the periods of highest activity.