This book deals with land productivity. Agriculture took the largest share of GNP before the mid-19th century and so economic growth must focus on agricultural transformations and measurements of agricultural productivity and its determinants. The 1963 study by B.H. Slicher van Bath on yield ratios across Europe was epoch-making. But more recent studies point to the necessity of placing and analysing land productivity more clearly within agricultural, ecological and socio-economic contexts. This publication, made by the CORN research team, reflects the new developments and findings in this field, for the North Sea area from the Middle Ages to the 20th century. The book consists of three sections: the first contains national longterm overviews for each of the North Sea countries; the second part presents several case studies which examine the relationship between land productivity and agro-systems; and the last part consists of general comparative studies. The publication thus hopes to advance our understanding of developments in land productivity and to build the material for further research. This book deals with land productivity and agro-systems, and reflects the new developments and findings in this field by placing and analysing land productivity more clearly within agricultural, ecological and socio-economic contexts.