Versailles Cathedral is a Roman Catholic cathedral and national monument of France. It is the seat of the Bishop of Versailles, created as a constitutional bishopric in 1790 and confirmed by the Concordat of 1801.
The cathedral was built as the parish church of Saint Louis before becoming the cathedral of the new diocese. The building is of the mid-18th century: the first stone was laid, by Louis XV in 1743 and the church was consecrated in 1754. The architect was Jacques Hardouin-Mansart de Sagonne (1711-1778), a grandson of the famous architect Jules Hardouin-Mansart. In 1764 Louis-François Trouard added the Chapelle des Catéchismes to the northern transept.
During the French Revolution it was used as a Temple of Abundance, and badly defaced.
It was chosen and used as the cathedral by the post-Revolutionary bishop, who preferred it to the church of Notre-Dame in Versailles, which had been the choice of the preceding constitutional bishop. Its consecration as a cathedral was however severely delayed, and was not performed until 1843, by the diocese's third bishop, Louis-Marie-Edmond Blanquart de Bailleul.
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.