A church at the site of Sant'Agata was present by the 8th century, when the neighborhood was located outside the city walls, but after the 1184 fire destroyed the ancient church, it was reconstructed in the 15th-century in Gothic style. Destruction by fire of this church was somewhat paradoxical, since Saint Agatha was the saint invoked for protection against fires. Further modifications were completed along the centuries, leading to a pastiche of styles. The incomplete 14th-century facade has a Renaissance architecture facade, decorated with Baroque statuary.
Inside, the presbytery dates from the 15th century, the ceiling from the 16th century, the altars and fresco decoration from the 1680s, and the chapel of the Santissimo Sacramento is from the 18th century. The main altarpiece depicting Sant'Agata with Saints Peter, Paul, Lucia, Apollonia standing before the cross (1522) is a masterwork by Francesco Prata from Caravaggio.
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.