The author owes a special word of thanks to Hans Koot for making available the data and draft chapters of the large-scale Ypenburg excavation. Okke Dorenbos, Hester van den Ende and Tom Hazenberg were also most helpful. For information, comments and useful discussions I would moreover like to thank Luc Amkreutz, Corinne Bakker, Peter van den Broeke, Joanne Mol, Bert van der Valk and Jørn Zeiler. Illustration 1 is by Walter Laan, the histograms are by the author and Medy Oberendorff made the other illustrations. The English translation is by Susan Mellor.