In the previous chapters, the archaeological remains of the military, the urban, and the rural communities that lived in the research area during the Roman period were described. This chapter summarizes these data, and the habitation history of the research area is discussed chronologically. Here, events that have been archaeologically observed in the research area are analyzed in the context of larger historical events in the Roman period in north-west Europe. Where relevant, archaeological data from surrounding regions are incorporated as well.

THE FIRST HALF OF THE 1ST CENTURY

An important observation with regard to the habitation history of the research area is the gap in habitation between the late Iron Age and the period around 50. This discontinuity can be explained by changes in the natural landscape, such as the stronger influence of channels from the sea, subsidence, increased water in the peat area, sand drifts and soil degradation of the beach ridges. However, these environmental conditions will not have had such an influence in the entire area that habitation on a larger scale was no longer possible. Another reason for the discontinuity may be the military operations of Julius Caesar in the more southern Gallic area, which certainly impacted neighboring regions. This can be seen from the fact that the gap in the habitation is not only present for the research area, but also applies to the central Dutch river area, the northern part of the Menapian civitas, and the Meuse-Demer-Scheldt area. In all these areas there is a break in the habitation record in the 1st century BC. So, Caesar's campaigns may have contributed to the disappearance of the habitation in the research area in the 1st century BC.

Nevertheless, there are indications that the area between 100 BC and 50 may not have been completely empty. People probably lived locally in the area although it may not have been many people. This means that in addition to the sparse rural habitation, which can be regarded as a remnant of the late Iron Age, the oldest features that were found in the research area are of Roman-military signature. These include some castella and the remains of a possible fort at the former airport in Valkenburg, all dating from the period 39-41. The forts themselves were probably not in continuous use, but only if they were needed, such as during military campaigns.