The Abbey of Saint-Gildas is dedicated to St. Gildas (c. 500–570) who was a British historian and cleric. He is one of the best-documented figures of the Christian church in the British Isles during this period. According a legend Gildas established the abbey, but there are no written evidences. Buildings were destroyed by Norman raids in the 10th century.
The first known record dates from 1008 when the abbey was restored by the order of Geoffrey I of Bretagne. The new inauguration was held in 1032. The heyday of Saint-Gildas Abbey was in the 11th-14th centuries. During the Hundred Years' War most of the archives were destroyed. The monastery started to decay in the 16th century. The nave of the church collapsed in 1668 when a lightning hit it.
the next restoration took place in the late 1600s. The abbey church was moved as a parish church during the Great Revolution in 1796.
References:The Clementinum is a historic complex of buildings in Prague. Until recently the complex hosted the National, University and Technical libraries, the City Library also being located nearby on Mariánské Náměstí. The Technical library and the Municipal library have moved to the Prague National Technical Library at Technická 6 since 2009. It is currently in use as the National Library of the Czech Republic.
Its history dates from the existence of a chapel dedicated to Saint Clement in the 11th century. A Dominican monastery was founded in the medieval period, which was transformed in 1556 to a Jesuit college. In 1622 the Jesuits transferred the library of Charles University to the Klementinum, and the college was merged with the University in 1654. The Jesuits remained until 1773, when the Klementinum was established as an observatory, library, and university by the Empress Maria Theresa of Austria.