The Monastery of Santa María de Mezonzo is a Romanesque style former monastery. Although it probably dates back to the time of the Kingdom of the Suebi, the current monastery was founded as a double convent by Abbot Reterico. According to Antonio López Ferreiro, the monastery was donated to the Asturian-Galician king Alfonso III el Magno in 870. Justo Pérez de Urbel, after comparing the names of the confirmatory of several documents related to the monastery, thinks that the correct date is the one given by Hinojosa, that is, the year 930.
References:Saint-Georges de Boscherville Abbey is a former Benedictine abbey. It was founded in about 1113 by Guillaume de Tancarville on the site of an earlier establishment of secular canons and settled by monks from the Abbey of Saint-Evroul. The abbey church made of Caumont stone was erected from 1113 to 1140. The Norman builders aimed to have very well-lit naves and they did this by means of tall, large windows, initially made possible by a wooden ceiling, which prevented uplift, although this was replaced by a Gothic vault in the 13th century. The chapter room was built after the abbey church and dates from the last quarter of the 12th century.
The arrival of the Maurist monks in 1659, after the disasters of the Wars of Religion, helped to get the abbey back on a firmer spiritual, architectural and economic footing. They erected a large monastic building one wing of which fitted tightly around the chapter house (which was otherwise left as it was).