Population developments in the western European countryside not only show strong fluctuations during the later Middle Ages, but they also exhibit sharp regional differences. By investigating and comparing developments in three parts of the Low Countries this study tries to shed more light on the causes underlying these regional diversities. In this connection, particular attention will be paid to differences in the social distribution of landownership. Examination of the data at regional level indicates that property structures were indeed an important factor in late-medieval population trends. Later sections of the article investigate the various factors which shaped the interrelationships between population growth, density and property structures, thus contributing to a clearer comprehension of the different demographic histories of the three regions and a better understanding of regional diversities in late-medieval population developments in general.