The Castle of Guimarães was built under the orders of Mumadona Dias in the 10th century to defend the monastery from attacks by Moors and Norsemen. At the end of the 11th century the castle was heavily expanded and remodeled, under the direction of Count Henry, to act as his residence. The castle became the official royal residence from 1139, when Portugal became independent from the Kingdom of León, until circa 1200.
Between the end of the 13th and beginning of the 14th century, the castle was remodelled by King Denis, resulting in the form that stands to this day. In 1369, King Henry II of Castile invaded Portugal and encircled the castle of Guimarães, but was defeated by its population and forces. Sometime between 1383 and 1433, the two towers that flank the main entrance were order built by King John I of Portugal.
After the castle's demolition was abandoned in the 19th century, many of the houses, estates and lodgings around the castle were expropriated. The first attempts at restoration occurred during the mid-20th century.
Today Guimarães castle area is delineated by walls forming a pentagram, similar to a shield, that includes eight rectangular towers, military square and central keep. Originating in the foundations of a Roman structure, from the writings of Alfredo Guimarães, it was later elaborated on the French model, in its current the form of a shield, with reduced central yard and difficult accesses. It includes several Gothic characteristics, owing to its remodelling at the end of the 13th century, when the keep and residences were constructed (possibly over pre-existing structures).
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.