text: The period immediately after the 10th century marked the widespread application of several innovations in the field of mining and ore treatment: a shift to large-scale and better quality production. Medieval miners and metallurgists had to find solutions for the practical problems that limited former metal production, in order to meet the market demands for metals. This increased demand for metal was due to the population growth from the 11th to the 13th centuries. This growth had an impact on agriculture, trade, and building construction, including Gothic churches.
  The main problem was the inefficient means for draining water out of shafts and tunnels in underground mining. This resulted in the flooding of mines which limited the extraction of ore to shallow depths close to the surface. The secondary problem was the separation of the metal-bearing minerals from the worthless material that surrounds it, or is closely mixed with it. There was, additionally, the difficulty of transporting the ore, which resulted in subsequently high costs.
  The economic value of mining led to investment in the development of solutions to these problems, which had a distinctly positive impact on medieval metal output. This included innovations such as water power using waterwheels for powering draining engines, bellows, hammers, and the introduction of advanced types of furnaces.
  These innovations were not adopted all at once or applied to all mines and smelting sites. Throughout the medieval period, these technical innovations, and traditional techniques coexisted. Their application depended on the time period and geographical region. Water power in medieval mining and metallurgy was introduced well before the 11th century, but it was only in the 11th century that it was widely applied. The introduction of the blast furnace, mostly for iron smelting, in all the established centers of metallurgy contributed to the quantitative and qualitative improvement of the metal output, making metallic iron available at a lower price.
  In addition, cupellation, developed in the 8th century, was more often used for the refinement of lead-silver ores, to separate the silver from the lead (Bayley 2008). Parallel production with more than one technical method, and different treatment of ores would occur wherever multiple ores were present at one site. (Rehren et al. 1999).
  Underground work in shafts, although limited in depth, was accomplished either by fire-setting for massive ore bodies or with iron tools for smaller scale extraction of limited veins. The sorting of base and precious metal ores was completed underground and they were transferred separately (Martinon-Torres & Rehren in press, b).
  Permanent mining in Sweden proper begun in the High Middle Ages and did not spread to Finland until 1530 when the first iron mine began operations there.