Godesburg castle was built in the early 13th century on the Godesberg, a hill of volcanic origin, it was largely destroyed following a siege in 1583 at the start of the Cologne War.
The site has a controversial history. First mentioned in documents from the early 8th century, there was supposedly an old cult site and its name derived from the old Germanic Wotansberg, Woudensberg, or Gotansberg.
The fortress foundation stones were laid by a vicar upon the order of Dietrich I, the Archbishop of Cologne. After Dietrich's death in 1224, his successors finished the fortress; it featured in chronicles of the 13th through 15th centuries as both a symbolic and physical embodiment of the power of the archbishop of Cologne in his many struggles for regional authority with the patricians of the imperial city of Cologne. By the late 14th century, the fortress had become the repository of the Elector's valuables and archives, and by the mid-16th century, was popularly considered the lieblingssitz, or the favorite seat (home), of the Electors.
The fortification had been originally constructed in the medieval style and in the reign of Siegfried II of Westwald (1275–1295) successfully resisted a five-week siege by Count William of Cleves. Successive archbishops continued to improve the fortifications with stronger walls and expanded moats, adding levels to the central Bergfried, which was cylindrical, not square like many medieval donjons, expanded the inner works to include a small residence, dungeons, and chapel, fortified the walls, added a curtain wall, and improved the roads. By the 1580s, it was an elaborate stone fortress, and it had been enhanced partially in the style made popular by Italian military architects.
In 1959, the ruin was rebuilt according to plans by Gottfried Böhm, to house a hotel and restaurant. Today, the restaurant is still in operation, but the hotel tract has been divided into apartments.
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.