Hesperange Castle probably dates from the early 13th century when the Counts of Luxembourg gave Hesperange to the Lords of Rodenmacher who sided with the French when the Burgundians conquored Luxembourg in 1443. Maximilian of Austria dismantled the castle in 1480 and 1482 after battles with Gerard of Rodenmacher. In 1492, he transferred it to the Lords of Baden who had to pawn it in 1692 and could only reclaim it in 1740.
After the French captured the castle in 1796, the French government nationalized it and sold it by auction in 1798. Later parts of the ruins were sold individually and by 1820 seven houses stood on the castle grounds. Now a national monument, the ruins are still privately owned.
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.