The beginnings of smelting go back to the start of mining in the Upper Harz in the Early Middle Ages. In medieval metallurgy, so-called nomadic smelting (Wanderverhüttung) predominated. The smelting sites were only used for a few weeks and followed the logging of the requisite wood. For the charcoal that was needed for the reduction of the ore, oak and beech wood were especially well-suited. The billets of wood were located near the smelting sites. The low shaft kilns (Schachtöfen) were built of natural rock and earth from the vicinity, and were by no means simple in their construction. They could only be used for a few days of continuous furnace campaign. Fixed buildings were not erected. Over 200 slag sites and smelting sites have been archaeologically recorded from this smelting period. Since the 1980s the mining archaeology team of Lothar Klappauf and Friedrich-Albert Linke have carried out excavations and undertaken a considerable amount of archeological and archaeometallurgical research. The high medieval smelting technology of the 10th to 12th centuries at the Rammelsberg was well established and complex. The wood dweller (Silvani), i.e. those who were doing the smelting in the woodlands, were able to produce copper, lead and silver from the poly-metallic ores of the Rammelsberg.