Milengrad was built during the reign of Hungarian–Croatian King Béla IV after the Mongol invasion of 1241–1242. Around 1303, King Charles Robert donated the fortress to the Cseszneky family in compensation for their loss of Ipolyvisk Castle. The counts Cseszneky sold it soon to Ban Mikcs, who, in 1309, ceded the lordship to the Herkffy family. In 1536, by the marriage between Katalin Herkffy and Miklós Patačić, Milengrad became the two families' shared property. In the 17th century, the Herkffy family became extinct, and the Patačićs followed in the 19th century. Due to the constant warfare with the Ottomans, and probably as well to an earthquake, by the late 17th century several walls of Milengrad fell down, and in 1683 it was already mentioned as arx diruta, a castle in ruins.
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.