The Castello Normanno ('Norman Castle'), or alternatively the Castello di Aci, is situated on a rocky outcrop jutting out into the sea. Its precise date of construction is uncertain, but it was important to the development of its region during the Middle Ages. During the War of the Sicilian Vespers, it was subject to Roger of Lauria. It was besieged more than once, and was briefly controlled by the Spanish. It is currently a museum.
The town of Aci Castello developed around the castle, which was built in 1076 by the Normans upon the foundations of a 7th-century Byzantine fortification. In 1169, Aci Castello started to expand after an eruption of Mount Etna made the towns in its vicinity uninhabitable. The castle later became the property of the Bishops of Catania.
In 1296, Roger of Lauria, admiral of the Aragonese fleet during the War of the Sicilian Vespers, was granted the fief of Aci and its castle as a reward for his faithful service to King Frederick III of Sicily. When relations between the two men soured and di Lauria transferred his loyalties to the Angevins, the castle was besieged and captured by King Frederick and di Lauria stripped of his fiefs. In 1320, the castle and Aci were taken from Roger's descendant, Margaret of Lauria and given to Blasco II de Alagona. Whilst the latter was away defending Palermo from the attacking Angevins, Bertrando di Balzo sacked Aci in his absence.
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.