The ancient city of Ialyssos extended around the hill of Filerimos, which was the ancient acropolis where there are remains of buildings from the Archaic, Byzantine and Knights' periods. The temple of Athena Polias, which dates to the 3rd-2nd centuries BCE, was built over the site of an earlier Classical temple, to judge from from the evidence of a 5th century BC floor and terra-cotta antefixes found there. The depository on the west side produced pottery and votive offerings dating from the 9th to the 5th centuries BC.
In addition to the cult of Athena Polias, in Ialyssos there are also references to a cult of Zeus Polias. In the Early Christian period (5th-6th centuries AD) a three-aisled basilica with an atrium was built on the remains of the ancient temple, in the north aisle of which a single-aisled church with a cupola was constructed in the 10th century.
In the time of the Franks this site was occupied by a medieval monastery and church.
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.