This study challenges two general opinions concerning the beginning of iron-making in blast furnaces in early medieval times in one of Sweden’s oldest mining district, (I) that iron was the reason for colonisation in early medieval times and (II) that independent “mining-peasants” (Sw. bergsmän) colonised the medieval mining fields and developed iron-making.By using different geographical sources and methods (such as spatial distribution of ancient remains and place-names, analysis of cadastral maps and written sources and pollen analysis) a chronology has been established. In the surroundings of the medieval mining fields there is evidence of prehistoric agricultural activities. The beginning of mining activities has also been dated back to 950 AD, 200-250 years before the first dated blast furnaces. By the turn of the 12th century an extensive expansion of iron-making in blast furnaces takes place. Iron became more important than farming. The blast furnaces shall be looked upon as the physical expression of investments and exploitation from representatives from the high aristocracy. In the initial stage the activities at mining fields and blast furnaces were supported from manors. During the 13th century a gradual emancipation took place and the mining districts become more independent from the manors and more self-sufficient of provisions and fodder. During the early 14th century the king took control over large parts of the area, while the aristocracy kept control over certain properties. These properties developed into iron works during the 17th and 18th century. The properties controlled by the king underwent further emancipation and owners of these properties appear as independent “mining-peasants” in late medieval times.