San Gregorio is a former church founded in the 9th century and, in the 13th century, it became a Benedictine abbey. In the mid-15th century it was rebuilt to the current appearance under design by Antonio da Cremona. In 1775, after a long period of crisis, the monastery was closed and in 1807, after the Napoleonic occupation of Italy, also the parish church was suppressed. Deconsecrated, it was converted in a mint laboratory and then an art restoration center. It is now closed and not used.
It has a Gothic exterior with an ogival portal, elongated mullioned windows with ogival top, and apse.
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.