San Pietro in Ciel d'Oro (Italian for 'Saint Peter in Golden Sky') name refers to the mosaics of gold leaf behind glass tesserae that decorates the ceiling of the apse.
A church of Saint Peter is recorded in Pavia in 604; it was renovated by Liutprand, King of the Lombards (who is buried here) between 720 and 725. The present Romanesque church was consecrated by Pope Innocent II in 1132.
The church is the resting place for the remains of Augustine of Hippo, who died in 430 in his home diocese of Hippo Regius, and was buried in the cathedral there, during the time of the Vandals. According to Bede's True Martyrology, the body was removed to Cagliari, Sardinia by the Catholic bishops whom the Arian Vandal Huneric had expelled from north Africa. Bede tells that the remains were subsequently redeemed out of the hands of the Saracens there—by Peter, bishop of Pavia and uncle of the Lombard king Liutprand—and deposited in the church of Saint Peter about the year 720.
In January 1327 Pope John XXII issued the papal bull Veneranda Santorum Patrum, in which he appointed the Augustinians guardians of the tomb of Augustine (the Arca di Sant'Agostino), which was remade in 1362 and elaborately carved with bas-reliefs of scenes from Augustine's life. The actual remains of Augustine, however, were no longer identified. Then, on October 1, 1695, illiterate stonemasons working in the crypt altar removed paving blocks and discovered a marble box. Within it were other boxes; in the third box were fragments of wood, numerous bones and bone fragments, and glass vials. Some of the workers later claimed to have seen the name 'Augustine' written in charcoal on the top of the box. A factor complicating the authentication of the remains was that San Pietro in Ciel d'Oro was shared by the two Augustinian religious orders in bitter rivalry. The controversy on the authenticity of the bones resulted in broadsides, pamphlets and books. In 1728, Pope Benedict XIII's intervention in Pavia resulted in his approval of the authenticity of Augustine's bones discovered in the church of San Pietro in Ciel d'Oro.
The Augustinians were expelled in 1700, taking refuge in Milan with the relics of Augustine, and the disassembled Arca, which were removed to the cathedral there. The erstwhile cathedral in Pavia fell into disrepair; it was a military magazine under the Napoleonic occupation. It was not reconstructed until the 1870s, under the urging of Agostino Gaetano Riboldi, later Cardinal Riboldi, and reconsecrated in 1896 when the relics of Augustine and the shrine were once again reinstalled.
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.