The basilica of St. Plechelm is a Roman Catholic church dedicated to the 8th-century Irish monk Saint Plechelm, whose festival on 15 July has been on the calendar of the medieval diocese of Utrecht ever since his canonisation in the 10th century.
The oldest parts of the existing building date from the middle and the second half of the 12th century, but the history of the church goes back to the 8th century, when the traveling missionary Plechelmus founded the first church on the site, the Silvesterkerk, initially dedicated to pope Silvester and sometime before 954 rededicated to Plechelmus himself (canonised after the elevation of his relics).
In 954, bishop Balderik of Utrecht founded a chapter in Oldenzaal and expanded and restored the 8th-century church, allowing the relics of Plechelmus used on his canonisation to be transferred to it. The current tower was erected around 1240. The church was enlarged in Gothic style in 1480s.
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.