Aberystwyth Castle was built in response to the First Welsh War in the late 13th century, replacing an earlier Motte and bailey castle located a mile to the south. The current castle was rebuilt in its current location by Edward I of England in 1277 after the end of the first war against Llywelyn ap Gruffydd Llywelyn the Great's grandson. The Welsh took the castle in 1282 at the start of the 1282 war and burned both the castle and the town. Under master mason James of St George, the castle was eventually completed in 1289, though it was sieged extensively during the revolt of Madog ap Llywelyn in 1294–5.
During a national uprising by Owain Glyndŵr, the Welsh captured the castle in 1404, but it was recaptured by the English four years later. In 1637 it became a Royal mint by Charles I, and produced silver shillings. The castle was slighted by Oliver Cromwell in 1649.
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.