ABSTRACT
The western part of the forest mass was considered a public forest in the early Middle Ages, and much of it had been converted to arable field by the eleventh and twelfth centuries. The extent of forest in early medieval Flanders suggests several conclusions that can help explain its economic development. The polyptychs show intensive agriculture under a powerful central direction, much better organized and with more densely populated farms than people have any reason to think was usual on lay properties. The polyptychs give information about agricultural routine, personal status of the farmers and village and field forms and population. This expansion in effect created the open-field, nucleated village in densely populated southeastern Flanders. It was accompanied by the spread of three-field agriculture, which had been known earlier in the adjacent regions of northern France. Toponymy has also advanced our understanding of field forms and the situation of the farmers.
