The Church carried out an immense task of evangelisation during the eighth to tenth centuries. The parish became the basic social environment for the agricultural communities. The monasteries played an important role in the spreading of culture. Religious buildings led the development of Romanesque art.

The Church had a specific role in the maintenance of law and order. In order to protect itself against feudal attack, the Church hierarchy established legal instruments such as the Pau i Treva de Déu (Peace and Truce of God). The work of Abbot Oliba exemplifies the cohesive and constructive role of the Church.