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:Rosenborg Palace was built in the period 1606-34 as Christian IV’s summerhouse just outside the ramparts of Copenhagen. Christian IV was very fond of the palace and often stayed at the castle when he resided in Copenhagen, and it was here that he died in 1648. After his death, the palace passed to his son King Frederik III, who together with his queen, Sophie Amalie, carried out several types of modernisation.
The last king who used the place as a residence was Frederik IV, and around 1720, Rosenborg was abandoned in favor of Frederiksborg Palace.Through the 1700s, considerable art treasures were collected at Rosenborg Castle, among other things items from the estates of deceased royalty and from Christiansborg after the fire there in 1794.
Soon the idea of a museum arose, and that was realised in 1833, which is The Royal Danish Collection’s official year of establishment.