As the Bard Fortress, Champorcher Castle also belonged to the powerful Lords of Bard, until the fratricidal war between William and Hugo in 1212. Little is known of this early building: we know that it was burned down by order of Hugo of Bard, which might suggest that it was constructed mostly of wood, like many buildings in the late Middle Ages. It was probably reconstructed in the same century, and definitely before 1276, when already it needed to be roofed with wooden tiles.
Following the popular tradition, the castle was built on the Corseria (currently the sacristy), with a chapel that would later become the first parish church.Of the ancient building, it remains the square-plan tower (about six metres per side) with swallowtail merlons south-west of the church. It was used during the Middle Ages as a watchtower. Access is via a door which is can only be reached using a ladder placed four metres above the ground.
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.