This report presents the results of the research project Swedish and Finnish in the cultivated areas of Upper Norrland. The cultural landscape as a mirror of social organisation. The project has been supported by a grant from the Swedish Council for Research in the Humanities and Social Sciences during the years 1997-1999. The results of the investigation are presented in two parts. Part I is based on analyses of cadastral maps from the late 17th and early 18th centuries of villages known at least as early as the mid 16th century. In these maps, a recurring feature, gårdsgärdor, i.e. consolidated plots of land containing farm buildings and scattered arable areas, can be found in the whole of the vast investigated area, from the Ume to the Torne river valleys as well as on the Finnish side of the Bothnian Gulf. A region could thus be defined in which the original basis for the economy has been fishing and hunting. In this region, a southern or Swedish influence in the shape of an open field arable could be found on the western side of the Gulf up to and including the Kalix river valley whereas this feature was completely absent on the eastern side and in the Torne river valley.Part II deals with the rapid shore regression in the area and its effects on the landscape and resource utilisation. In many places cultivation of any importance probably became possible only during the late Middle Ages (14th-15th centuries). Hunting, especially for seal, and fishing, both activities involving groups of people, were for a long time more important than cereal cultivation. Examples are given of areas of meadowland situated on recently emerged land that were owned by several villages in common. As has been shown in the case of Ostrobothnia, Finland, this ownership could have its roots in a previous joint use of the area as fishing waters, and the predecessors of the landowning villages may have been earlier teams for fishing. This presumed original resource utilisation by groups of people, coming from the south as well as from the east, may explain why many of the villages in the area so rapidly grew large compared to habitations in most other parts of Sweden.