The current appearance of Castel Sant’Angelo in Rome is the result of numerous interventions on the structure that was originally an imperial tomb.
In the second century AD, the emperor Hadrian, a lover of oriental culture, decided to build a mausoleum for himself and his family in the form of a mound, in an area beyond the Tiber river outside the city walls. The tomb was connected to the city by a bridge, called “Pons Aelius,” on which the current Ponte Sant’Angelo with statues by Bernini was later built.
In 271, the emperor Aurelian extended the walls of Rome; the mausoleum was thus comprised within them, losing its funereal function and becoming a fortress. Its role was crucial when Odoacre’s Goths conquered Rome in 476, and more than a thousand years later, in 1527, during the Sack of Rome by Landsknecht mercenary soldiers.
The structure of the building naturally lent itself to being unconquerable. For this reason, the “Adrianeum” became a very important place during the power vacuums of the Middle Ages, when the Theophylact, then the Crescenzi and Pierleoni families fought bitterly for its ownership.
Last came the Orsini, with whom the fate of the Castle underwent a turn: Pope Nicholas III, born Gaetano Orsini, in 1277 was the owner of the structure as well as pontiff. From that moment on, it became part of the papal property and linked its name to the Archangel Michael, who appeared in AD 590 to Pope Gregory the Great during a procession. It is said that the apparition of the angel put an end to a deadly plague and thus Pope Nicholas ordered a chapel built in memory of the miraculous event: from that moment on, the Castle was dedicated to the Healing Angel, with the statue of the angel returning his sword to its sheath atop the fortress designed by Antonio da Sangallo.
In the Renaissance, Pope Julius II decided to transform the bastion into a comfortable residence, requesting the work of Michelangelo for the side façade of the Chapel of Saints Cosma and Damiano and Giuliano da Sangallo for the loggia.
Pope Julian II refurbished the Passetto, a covered, fortified passageway which connects the Castle with the Vatican Palaces. In the last years before 1870 the Pope often used it, and the Castle became a prison for the Carbonari, patriots and opponents of the Pope, until the conquest of Rome by Garibaldi’s troops.