Romanesque architecture started around 1000 AD in the north of Italy, in the Lombardy, and spread rapidly throughout Europe. In spite of many regional and local variations, it was the first international art movement with a unified style. In Catalonia, this new artistic style arrived through Abbot Oliba (971-1046) who, in the towns of Ripoll, Cuixá and Vic, was the driving force behind the architectural renovation of the Catalan counties in the 11th century. Early Romanesque has elements from the classical world, local traditions and itinerant craftsmen. The buildings are practical and austere, their only external decoration being rounded arcading and pilaster strips, with thick walls capable of withstanding the weight of the barrel vaults. There are few windows or doors and the naves are usually separated by columns or pillars joined by semicircular arches. Improvements in techniques illustrate how the art of stonemasonry had been perfected in the 12th century , Architectural resources diversified and more sculptural elements were added to the decoration. The Catalan region of the Boí Valley became one of the centres of ecclesiastical Romanesque architecture.
From the 9th century, the land to the south of the Pyrenees became organised into counties that were part of the “Marca Hispánica” or Hispanic Mark. Iin the 10th century, the Catalan counties gradually achieved political and religious independence. The Vall de Boí, or Boí Valley, formed part of one of these counties: Pallars-Ribagorça, belonging to the house of Toulouse until the end of the 9th century. When the county became independent, a process of political and religious control over the territory started, ending up with the county divided into three new independent counties: Ribagorça, Pallars Jussà and Pallars Sobirà and creating the new diocese of bishopric of Roda.
The Vall de Boí was in the midst of this process. It became part of Pallars Jussà and most of the parishes became part of the Urgell bishopric, with only the church of l’Assumpció in Cóll continuing to belong to Roda. The lords of Erill, rulers of the vallee, used resources obtained from war booties to promote the building of churches in the Vall de Boí (Source: www.centreromanic.com).