The social, political, and economic stagnation that followed the Roman Empire affected Europe throughout the early medieval period and had a critical impact on technological progress, trade, and social organization. Technological developments that affected the course of metal production were only feasible within a stable political environment, and this was not the case until the 9th century (Martinon-Torres & Rehren in press, a).
During the first medieval centuries, the output of metal was in a steady decline with constraints in small-scale activities. Miners adopted methods much less efficient than those of Roman times. Ores were extracted only from shallow depths or from remnants of formerly abandoned mines. The vicinity of the mine to villages or towns was also a determining factor when due to the high cost of material transportation (Martinon-Torres & Rehren in press, b). Only the output of iron diminished less in relation to the other base and precious metals until the 8th century. This fact, correlated with the dramatic decrease in copper production, may indicate a possible displacement of copper and bronze artifacts by iron ones (Forbes 1957, 64; Bayley et al. 2008, 50).
By the end of the 9th century, economic, and social conditions dictated a greater need for metal for agriculture, arms, stirrups, and decoration. Consequently, conditions began to favor metallurgy and a slow but steady general progress developed. Starting from the reign of the emperor Otto I in the 960s, smelting sites were multiplied. New mines were discovered and exploited, like the well-known Mines of Rammelsberg, close to the town of Goslar in the Harz Mountains. Open-cast mining and metallurgical activities were mostly concentrated in the Eastern Alps, Saxony, Bohemia, Tuscany, Rhineland, Gaul, and Spain (Nef 1987). It was mainly German miners and metallurgists who were the generators of metal production, but the French and Flemish made contributions to the developments.