During the Middle Ages agriculture and agricultural labor was involved in a new system of values, due to the expansion of Christianity, and this valorization had a great impact on society and economic development of Western Europe. Agriculture was considered part of the artes mechanicae and peasants (laboratores) were recognized as one of the three orders of the social representation. However, in the 13th-15th centuries, there were some significant changes such as the shift from serfdom to contracted work, investments in agriculture by citizens, and the development of new connection between cities and the countryside. Historical treatises on agriculture and other public sources provide evidence of these news ideas, that viewed agriculture as the “most useful and necessary” craft.