The walls of the ancient Fishermen's Chapel are reputed to date from the middle of the 6th century, but some authorities give a later date. It is however only a few monastic chapels survived the destruction of over fifty others at the hands of the Reformers in the 16th century. The material used in the chapel is the same as was used in the parish church: limpet shells crushed and dissolved with boiling sea-water. The stone roof was raised in the 14th century. The monks of that period evidently found the roof too low and squat for wall paintings. These were discovered in 1918. After a severe storm, colour was revealed on the ceiling and a picture of the 'Assumption' was seen, but in a damaged condition. But underneath the plaster was found another painting, 'The Annunciation', of about 1310-1315 A.D. At the foot of this painting are seen fourteen figures, supposedly members of an old Jersey family, the head of which had paid for this painting.The floor was restored to its earlier level in the 1980s to the medieval level, and the 'low, squat' aspect of the chapel which appears in early photographs is now gone, as the proper proportions can be seen.
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.