The occupation history of the coastal area of the northern Netherlands in the 4th and 5th centuries AD has been the subject of heated debate in the past. It still has not been decided whether migration or acculturation underlie the changes in the material culture that occur in the 5th century. In this article, the pottery from the terp settlement of Ezinge in the province of Groningen was compared to the pottery from some other settlements, in particular Midlaren-De Bloemert in northern Drenthe and the terp settlement of the Feddersen Wierde on the coast of Niedersachsen, in order to investigate the occupation history of the northern Netherlands in the 4th and 5th centuries.
The number of pottery individuals, associations of pottery and a continuous typological development indicate that both Ezinge and Midlaren-De Bloemert were inhabited continuously from the middle Roman Iron Age until the early Middle Ages. While these pottery assemblages show how continuity can be recognized, they implicitly also show what the characteristics of discontinuity in this period might be: no finds from the period of the hiatus, no continuous pottery development and no associations of pottery from the 3rd century with pottery in Anglo-Saxon style. These characteristics apply to a large part of the terp region of the northern Netherlands. Only some terps in Groningen and possibly in Oostergo remained inhabited during the 4th century.
The abandonment of the terp region already started in the 3rd century. It may have been caused by natural as well as social circumstances. The last inhabitants left no later than AD 350, if we follow Lanting and Van der Plicht (2010), but most terps were already deserted by that time. The area was reoccupied as from the early 5th century. From the small number of finds from this period in most terps, it may be inferred that reoccupation only started on a small scale. Since there are considerable regional and local differences, it is not possible to give a general date for the occupation hiatus.
The reason why some terp settlements in well-drained areas in the province of Groningen remained inhabited, whereas terps in well-drained areas in Friesland were abandoned, must lie in the social network these settlements were part of. Already from the beginning of the Roman Iron Age, Groningen and northern Drenthe had been part of a socio-cultural network, which reached far into the east and which shared the same style of pottery. Within this network, there was frequent social intercourse, which involved the exchange of gifts and marriage partners. It also enabled the rapid spread of stylistic elements. Soon after the Anglo-Saxon style developed in the 4th century in the Anglo-Saxon core area, Schalenurnen were adopted in Ezinge, while in Midlaren, decorated pots in Anglo-Saxon style were used as cremation urns. These forms and their decoration were adopted by the local population and combined with their local ware. The network that is represented by this pottery, provided a solid social background to the remaining inhabitants of the Groningen terp region during the 4th century.
The situation in the Frisian terp region was different. This area had only come under the influence of this eastern socio-cultural network in the 3rd century, at a time when part of the population had already left. This did not stop the emigration process. The Frisian terp region, especially Westergo, was virtually deserted as from the beginning of the 4th century.
The coastal area was reoccupied in the course of the 5th century, only on a small scale. The abandoned terps in Groningen may have been repopulated from still inhabited terps in the area itself, or from nearby Drenthe. However, the population of these areas was not large enough to occupy the entire terp region, including the Frisian terps. Immigrants from elsewhere, but within the same ‘Anglo-Saxon’ network, must have occupied many of the abandoned terps. The new settlers as well as the remaining inhabitants of Groningen terps and of northern Drenthe were part of the same network. Through this network, not only the Anglo-Saxon pottery style, but also other cultural elements such as a different settlement structure and a new type of burial ritual, which have traditionally been associated with Anglo-Saxon immigrants, spread over the entire repopulated area. Migration as well as acculturation thus played a role in the introduction of new cultural elements during the Migration Period in the northern Netherlands.