This volume deals with the social implications of land transactions, especially with the role of personal and institutional networks in a precapitalist society. The four authors discuss different aspects of the relationship between three monasteries (two Cistercians, Montederramo and Oseira, and one Benedictine nunnery, Ramiranes) and the peasant communities around them in thirteenth-Century Galicia. They use a Data Base to register 2500 'foros', the typical Galician land contract and more than 8000 people and their goods.The thesis of the authors is that monasteries did not exert their authority upon powerless peasants, but constraint by preexisting networks of local people. Most of the peasants involved in the transactions turned out to be members of 'middle groups' like knights, squires or upper peasants. The book is especially important for all those interested in social perspectives as a means to understand the medieval economy.