The temple used to be the Priory of the Royal Abbey of Montearagón, a privilege it held until 1571, when it became part of the Diocese of Huesca, and known at this time as the Collegiate Church: a high-ranking temple with a chapterhouse of clergy, incumbents or prebendaries that prayed using Gregorian rites in the choir every day and collected tithes and other church duties from the vast territory under its jurisdiction. Of the Arabian fortress (10th century) only the tower, base and walls remain. The current building rests on the foundations of the Romanesque church dating back to the 12th century, of which the belfry and crypt beneath the presbytery have survived.

The collegiate church was erected between 1541 and 1559 by Pedro de Irazábal from Guipuzcoa. He based his construction on the Cathedral El Salvador ("la Seo") in Zaragoza and the Cathedral of Barbastro. A temple marking the transition from the Gothic to the Renaissance style. It has a square ground floor (Hallenkirche), with the three naves each of being of the same height. Round arches. Fascicular columns in the main nave, cylindrical columns in the presbytery and ringed columns in the choir. Star-shaped ribbed vaults, decorated with 14 different motifs. The interior walls are completely clad in mortar and plasterwork. The main entrance in the Renaissance style is the work of the master sculptor Juan-Miguel de Orliens and his assistant stone-mason Juan de Escorz, who crafted it in 1611.