The two archipelagos of Orkney and Shetland, which form the Northern Isles of Britain, are an active focus of archaeological research. The rich Neolithic heritage of Orkney has been acknowledged by the granting of World Heritage status. Although set in both a biogeographically peripheral position and within what may be considered to be marginal landscapes, these North Atlantic islands have a large number of settlement sites with long occupational sequences, often stretching from the Neolithic to the Late Iron Age or into the Norse period. The mixed paleoeconomic strategy presented by three of these settlements¿Tofts Ness, Sanday, Orkney (excavated 1985¿1988); the Iron Age sequences at Old Scatness, Shetland (excavated 1995¿2006); and Late Neolithic and Bronze Age cultivated middens from Jarlshof, Shetland (investigated in 2004)¿provide the core of the evidence discussed within this paper (the radiocarbon chronologies for the key sequences from these three sites are provided as Appendix 1). The role of the prehistoric paleoeconomy is argued to be of central importance in the longevity of these settlements. In particular, barley production is evidenced on all three sites by the plant macrofossils and by the human investment in the creation and management of manured soils, providing an infi eld area around the settlement. This paper focuses on the identifi cation of these anthropogenic soils in the archaeological record. The investment in and management of these arable soils provides clear evidence for resource creation on all three sites. It is argued that these soils were a crucial resource that was necessary to support intensive barley cultivation. The intensive management implied by the presence of these soils is seen as a catalyst for sedentary living and sustainability within a marginal landscape. The evidence also demonstrates the continuity of agricultural practice from the Neolithic to the Iron Age together with the social dynamics that such a practice generates. This paper is in two parts: the fi rst section examines in detail the evidence for the presence of anthropogenic soils and the mixed economic strategies for the Neolithic and Early Bronze Age presented by the evidence from Tofts Ness and Jarlshof. The evidence for the continuity of this intensive strategy of soil management is seen from the later evidence of the Bronze Age and Early Iron Age at Tofts Ness and the Middle Iron Age evidence at Old Scatness. The second part of the paper examines the importance of these soils as an inherited resource within the Neolithic and Early Bronze Age paleoeconomic system. Two models are presented. The fi rst examines the cyclic importance of human creation and maintenance of small arable plots to high barley production yields and therefore to site viability, and the effect this has within a mixed resource system in providing settlement viability through time. The second explores the theoretical land and seascape that would provide this mixed resource base.