This Issue on Natural Resources and productive activities in the Iberian Peninsula during the Middle Ages constitutes another important contribution to the line of work in which the RENAP Project has been engaged for some time. The topics they address expand, on one hand, the existing studies on the territories of the Crown of Aragon, such as the relationship between salt exploitation and livestock consumption in medieval Catalonia,  wool manufacturing in Castelló de la Plana at the end of the 15th century , or the cultivation and exploitation of madder as a dye raw material in southern Valencia. On the other hand, they analyze various issues affecting other economic regions of the Iberian Peninsula, such as the use of linen in Andalusia and the environmental problems it caused in the 15th century. One of the articles focuses on the Kingdom of Murcia and presents it as one of the pioneering territories in the use of water mills with rodezno and regolfo within late medieval Castile. Finally, a last study addresses the emigration of technical master craftsmen and the transfer of technologies from one city to another, through the analysis of Genoese influence on the silk industries of the Crown of Aragon and Castile during the 15th and 16th centuries. In sum, as can be seen, the debate raised by these contributions transcends local history and highlights issues that once again invoke the various historiographies of the surrounding countries in Mediterranean Europe  (From the Introduction).