The iron metallurgy in Switzerland during the Early Medieval Period (mid 5th - 10th century AD)
After the collapse of the Roman Empire, a reorganization of the trade and industry was to take place. From the 6th century onwards, the archaeological evidences indicate the spread of the iron production all over Switzerland. Most of the bloomery furnaces and slag heaps excavated in the Canton of Vaud (Les Bellaires, Montcherand) date back to the Merovingian period. In the Central Jura, the oldest dated slag heaps are the same age (Boécourt, Corcelles). In the area of Schaffhausen, the trend seems to be similar. On Mont Chemin near Martigny VS in the Alps, all the dated slag heaps are Merovingian. On the Salève mountain (France) near Geneva, several sites are also dated of the same period. In both the italian Alps and the french Jura, there are evidences from this time period.
On the other hand, the use of iron gradually decreased. Only a small number of iron objects are known from Early Medieval settlements, while numerous and wonderful weapons and belt buckles are found in graves. This demonstrates a shift in the use of iron from the Roman to the Early Medieval Period.
Archaeological evidence for blacksmithing activities is scarce but, in fact, only few settlements have been investigated. A smithing workshop has been found at Sézegnin GE. At Develier-Courtetelle JU, in the middle of the Delémont valley, a hamlet of several farmsteads has been excavated recently. Here, iron smithing was a major activity. Other sites also provide smithing slags but in smaller amounts.
During the early Middle Ages, the production and working of iron was important in Switzerland. The many tons of reduction slags dated to this period seem to testify to a production sufficient for the needs of the local market. It may even be possible that the country started to export iron to other areas.