Alfonso VII of León and Castile
Its foundation is due to the king Alfonso VII of León and Castile, in fulfilment of a promise he made in the siege of Coria. For this project, the king brought in 1142, from the abbey of Berdoues in Gascony (France), a community of Cistercian monks, with their abbot Rodulfo, who stayed in a very poor building built in a place called Cántabos, located in the municipality of Fuentelmonge. The chosen place had shortage of water and a transfer to the lands near the Jalón river, which took place in 1162, was decided.