As late as the beginning of this century, the question discussed in this publication – the role of the North Frisian islands within Early Medieval trading networks – could not have been answered in any detail. When a hoard of 87 denarii and sceattas, deposited together with a few shards of Frankish glasses, fragments of basaltic lava from Mayen and sherds of wheelthrown Ribe ware, was discovered in the area of Goting cliff in 1976, it indicated that trading vessels must have repeatedly visited the islands of Amrum, Föhr and Sylt between the 8th and 11th centuries. However, the social importance of trade and its organisation remained subject to speculation. It is only the systematic analysis of aerial survey data, initiated in 2006, which in combination with large-scale geophysical work led to the discovery of several well-preserved settlements. These were first investigated in the course of rescue excavations and later in much more detail as part of the “North Sea Harbours” project, funded by the Deutsche Forschungsgemeinschaft. This yielded an exceptionally diverse and high-quality set of fi nds and features, thus providing the perfect opportunity for re-writing the Early Medieval settlement and economic history of the North Frisian islands. This task has been tackled by Bente Sven Majchczack, who not only directed several of the excavations, but also grew up on the island of Föhr. The results of his investigations were accepted as a doctoral dissertation at the University of Rostock and are presented in this volume.