The original castle on the Marienberg, a hill which was first settled in the late Bronze Age, was probably a small fort built early in the 8th century by the Franconian-Thuringian dukes, together with a church which in 741 became the first church of the Würzburg bishops. From 1200 an unusually large castle was built, which was extended during the late Middle Ages and the Renaissance.
Following the storming of the castle in 1631 by the Swedes, Prince-Bishop Johann Philipp von Schönborn built a circle of massive bastions to protect the Marienberg. In 1945 the fortress was almost completely burned out, and its reconstruction was only completed in 1990.
On the first floor of the Princes' Building Museum (administered by the Bavarian Palace Department), is the Bibra Apartment with valuable furniture, tapestries and paintings, the Princes' Hall with early Gothic arcatures and the large Echtersche family tapestry, as well as a treasury and vestment chamber from the era of the prince-bishops. On the second floor is the Main-Franconian Museum documenting the history of the fortress and town.
The 1,300 m2 Princes' Garden is accessible from the castle courtyard: it was reconstructed in 1937-38 on the basis of plans dating from the early 18th century.
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.