Santa Maria del Regno church, together with the annexed castle of which ruins remain today, was built in the 11th century by Giorgia, daughter of the Giudice of Torres, as a Palace Chapel. The church is mentioned in the Libellus Judicum Turritanorum of the 13th century.
The church was built in dark basalt stone by Pisan workers (the island in the Middle Ages was under strong influence from the maritime Republic of Pisa). The façade is divided into five sectors and has a salient-shaped façade. In the middle is the portal, surmounted by a double mullioned window. The whole exterior of the edifice is characterized by false columns (lesenes) and Lombard bands; on the right are the remains of the square bell tower, which is missing the upper part.
The interior, on a rectangular plan, has a nave and two aisles divided by columns whose capitals have flower motifs. The nave has a wooden trusses ceiling, while the aisles are groin vaulted. In the semi-circular apse is the large retablo, the largest 16th-century polyptych in Sardinia, located behind the high altar. The table portrays several prophets and saints, as well as episodes in the life of the Virgin Mary. In the middle, within a niche, is the wooden statue of Nostra Signora del Regno, a 'Madonna with Child' wearing royal symbols. The polyptych is dated 1515.
The church's columns have 17th-century paintings with Apostles and other Saints, while also present is a lesser retablo from the same school, a carved wooden pulpit and an epigraph celebrating the consecration of the church on May 7, 1107.
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.