According to Greek mythology, Troezen came into being as a result of two ancient cities, Hyperea and Antheia, being unified by Pittheus, who named the new city in honor of his deceased brother, Troezen. The ancient city of Troezen was one of the first cult centres in honour of the sea god Poseidon (in Greek mythology Poseidon is a forebearer of the former king Troezen after whom the city was named).
In 580 BC and in the face of the advancing Persian army Athenian general Themistocles proposed to the city assembly that all the women, children and elderly residents of Athens be evacuated to Troezen while able bodied men were sent to fight the Persians or to man the Athenian fleet. Although Athens was subsequently destroyed its citizens were spared.
During the Classical and Hellenistic periods numerous temples and other buildings were constructed in Troezen including a complex of buildings forming a sanctuary to Asclepius although this was somewhat overshadowed by its rival at nearby Epidauros. Other temples were dedicated to Artemis, Hippolytus, Athena and Aphrodite, traces of which can be found in a forest near Troizina.
In 230 BC the volcano at nearby Methana erupted causing severe earthquakes which destroyed many of the temples and buildings at Troezen leading to a decline of the sanctuary to Asclepius. During the Roman era many of these buildings were restored but as Christianity became predominant material from ancient buildings was used in the construction of churches as can be seen in the Diocese church which dates to the 6th century AD.
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.