Saint-Brieuc Cathedral was the seat of the Bishopric of Saint-Brieuc, one of the nine ancient dioceses of Brittany, and continues to be the seat of the enlarged Bishopric of Saint-Brieuc-Tréguier, as it has been known since 1852. Some of the relics of Saint Brieuc himself, the 6th-century founder, are still kept in the cathedral. The present building however was built in the 14th and 15th centuries.
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.