Between about 950 and 1050, a number of large to very large cities emerged in the Southern Netherlands, including Atrecht, Ghent, Bruges and Ypres. Their genesis was highly productive agriculture, connections between specialised economic regions and a textile industry with a far-reaching degree of division of labour. From 1050 to 1300, this growth increased exponentially. During a few centuries, a society remarkable for its time emerged on the North Sea coast in which 30 per cent of the population was engaged in the secondary or tertiary sector and lived in cities. The problem, however, is that in the absence of quantitative data, it is very difficult to measure the precise chronology, conjuncture and intensity of this growth. This exploratory project will develop a number of interdisciplinary methodological lines to identify different types of proxies for this growth: price and wage series, settlement history, topnymia, famines, monetary data, and in collaboration with archaeologists the interpretation of dendrochronological and other archaeometric data