115 1. For the concept of ‘innovation’ in the Middle Ages, see Paul Benoit, “Au four et au moulin : innovation et conjoncture”, in Patrice Beck (ed.), L’innovation technique au Moyen Âge, Actes du VI e Congrès international d’archéologie médiévale, Paris, 1998, p. 293-301; Catherine Verna, “Quelles sources pour quelles entreprises au Moyen Âge?”, in Francesco Ammannati (ed.), Dove va la storia economica? Metodi e prospettive, secc. xiii-xviii/Where is economic history going? Methods and prospects from the 13 th to the 18 th centuries, Atti della Quarantaduesima Settimana di Studi (Prato, 18-22 aprile 2010), Florence, 2011, p. 339-371; Id., “Innovations et métallurgies en Méditerranée occidentale (xiii e -xv e  siècles)”, Anuario de Estudios Medievales, t. 41/2, 2011, p. 623-644. About the importance of new energy supplies in the Middle Ages, see Paolo Malanima, Uomini, risorse, tecniche nell’economia europea dal x al xix secolo, Milano, 2003; S. Cavaciocchi (ed.), Economia ed energia: secc. xiii-xviii, Atti della Trentaquattresima Settimana di studi dell’Istituto in- ternazionale di storia economica F. Datini (Prato, 15-19 aprile 2002), Firenze, 2003. 2. Medieval iron in society, Papers presented at the Symposium in Norberg (Norberg, May 6-10 1985), Stockolm, 1985; Gert Magnusson (ed.), The impor- tance of ironmaking. Technical innovation and social change, Papers presented at the Norberg Conference (Norberg, May 8-13), Stockholm, 1996; Estanislau Tomàs I Morera (ed.), La farga catalana en el marc de l’arqueologia siderùrgica, Simposi Internacional sobre la Farga Catalana (Ripoll 13-17 setembre 1993), Andorra, 1995; Pierre Pétrequin, Philippe Fluzin, Jacques Thiriot et P. Benoit (ed.) Arts du feu et productions artisanales, XX e Rencontres internationales d’Archéol- ogie et d’Histoire d’Antibes, Antibes, 2000; Philippe Braunstein (ed.), La sidérurgie alpine en Italie (xii e -xvii e  siècle), Rome, 2001. 3. Jean-François Belhoste, “The origins of direct reduction water-powered ironworks: refections based on the evolution of terminology”, in La farga catalana, p. 385-398; Id., “Mutations techniques et flières marchandes dans la sidérurgie alpine entre le xiii e et le xvi e  siècle”, in La sidérurgie alpine, p. 516-592; Mathieux Arnoux, “Moulins à fer et Cistercian monasteries and water-powered iron-working: two case studies from medieval Tuscany Maria Elena Cortese Researchers who have worked on the history of iron production in the medieval period and the modern era have underlined the close connection between the appear- ance of technical innovations linked to the use of water power and increased productivity in this sector. After a long developmental period, leading up to the first applications of water power in activities other than simply milling wheat, a new phase began in the history of the European iron production: the iron-working process – although in many areas still based, for a long period of time, on the direct method of ore reduction – saw a consider- able development thanks to the use of water-wheels to operate hammers, and later also bellows. In all likelihood, the innovations, which appeared in the first few decades of 1100 in several different European mining areas, were the result of a series of small modifica- tions, and gradual improvements introduced in the production process as a whole 1 . Later on, we see a wider diffusion of the new metallurgical techniques 2 . Indeed, in 13 th century, more or less simultaneously throughout Europe, technical terms appear more and more often in the written sources, terms used by the notaries to refer to specialized produc- tion workshops, which seem to be unmistakeably connected to the use of water power (although only very rarely do the texts tell us explicitly whether the water-wheels were used to raise hammers, operate bellows, or do both things together) 3 . In this context, the