All Saints' Church is a chapel located in the Prague Castle complex. The site of the church was originally consecrated in 1185 and a Romanesque building built; the oldest parts of the current building date to a structure constructed by Peter Parler in the 14th century.
Although originally free-standing, the church was badly damaged in an 1541 fire which engulfed the palace and church. Through subsequent successive rebuildings and enlargements, the church became physically integrated with the palace, specifically Vladislav Hall.
The church holds the tomb of St. Procopius and his life is depicted on paintings on the walls. Although accessible from Vladislav Hall, the church is generally only open to the public during religious services and concerts.
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.