Alburquerque was conquered from Moors by Ferdinand II of León in 1166. It changed hands couple of times before was finally in the hands of Christians in 1217. The castle was built in the late 13th century.
In the mid-15th century Álvaro de Luna, Master of the Order of St. James, built the famous keep. But that is not the only identifying mark on this castle as it has several palace-style out buildings, some outer defence resources in the barbican and a curious pentagonal tower, crowned battlements with sharp points ending in balls. Furthermore, the fortress is protected by three levels of walls scattered with small towers and several doors.
In the early 18th century the city was in the hands of Portuguese and several Vauban-style bastions were added to the complex.
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.