According to tradition, the Irish bishop Kilian were killed with his fellows at the site of today Neumünster church. Bishop Megingoz built the first church on the site as a memorial for martyrs in the 8th century.
The next church was built around 1060 and renewed in 1250. The current Baroque appearance dates from the 18th century (1711-1722). In World War II the church was partly destroyed and restored later.
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.