Summary: Between 1599 and the end of the 1650s, the French Crown sustained a policy of land reclamation at a large scale. It was led by the French aristocracy who were helped by representatives of the merchant elites of Amsterdam, such as Hieronimus van Uffelen and Jean Hoeufft. The works in both Arles (Provence) and Petit Poitou (Poitou) show that land reclamation involved a radical change in society, reinforced the authority of the Crown in the areas concerned, and disrupted the former social balances built around the marshes. Thus, land reclamation aroused several conflicts which revealed its deep impact on the environment. So, this article demonstrates how the making of the modern state, backed by the development of European trade and banking, caused ecological and social changes by connecting the political and financial powers on a European scale.

In the long-term history of wetlands, the sixteenth century represents a turning point as at that time very large funds were injected into a new system of drainage. In the Low Countries and in northern Italy more than anywhere else, the conquest of the wetlands turned into an extensive business.

The change was particularly marked in Holland, where people were obliged to manage the consequences of the intensive mining of peat which had occurred during the Middle Ages. To drain the lakes created by the resulting subsidence, the Dutch employed new techniques, using wind-mills to divert water into canals and rivers.