On October 25, 1140, Alfonso VII of León and Castile gifted the Santa Maria de Yerga Church land for the purpose of building a monastery.
Internal problems were recorded between 1189 and 1210 when the General Council of the Order of Cistercians levied several accusations against the abbots.
[1] Similar charges appear to have been levied in subsequent years, but in 1197 a conspiracy was uncovered to remove the Prior of the monastery.
[2] In 1336 Don Juan Martínez de Medrano 'El Mayor' participated in the arbitration of the conflict over the property of the monastery of Fitero maintained between Navarra and Castile.
[4] King Peter IV of Aragon supported Navarre and a new peace treaty with Castille was signed on 28 February 1336.The matter was not resolved until 1373 when it was concluded that the Monastery of Fitero had always belonged to Navarra.
[2] As a result of the war and other problems, monastic life saw a significant moral and spiritual decline that went well into the XVI century.
[2] However, with the turn of the XVII century there was a spiritual and educational revival as the Cisterician Order made changes that required two monks from each monastery to attend university.
[5] In accordance with Cistercian monastic structures, the monastery consisted of a church, dormitory, refectory, and a guest house.
The monastery's territory, which had a collection of buildings and surrounding crop fields, was physically separated from the rest of the land by a wooden fence.
A short time after the relocation, the wooden fence was replaced by a wall made out of brick, rock, and mortar[5] However, this monastery was destroyed in 1159 when the bishop of Tarazona attacked and took over.
[5] During this time, the sanctuary, transept, supporting buildings on the eastern corridor of the cloister, library, sacristy, and chapter house were built.
The church's main design was heavily influenced by gothic architecture based on the inspirations imported from the French region of Burgundy.