The nineteen centuries of history of the Mausoleum of Hadrian are closely intertwined with the historical events of Rome.
Due to its tower-like shape and its strategic and dominant position, in late antiquity it was transformed into a fortress, and withstood countless sieges, starting with those of the Visigoths and the Vandals in 410 and 455 AD.
In 537 AD, during the terrible siege of the Goths of Vitige, General Belisarius put the barbarians to flight by breaking the ancient sculptures into pieces and throwing the pieces on the besiegers.
The Mausoleum of Hadrian was obviously inspired by that of Augustus, the first great imperial dynastic tomb, built in the Campus Martius, a place of great symbolic significance where the funerals of the most important figures were celebrated.
In turn, Augustus was inspired by the great Etruscan mounds but also by other famous Mausoleums, such as that of Halicarnassus which was one of the Seven Wonders of the world. The works began in 29 BC when Augustus returned from Alexandria. All the Roman emperors and members of the imperial family up to Nerva were buried there; Trajan was buried in the base of Trajan's Column.
Since there was no more room in the Mausoleum of Augustus, Hadrian decided to build a new imperial dynastic tomb that would celebrate the new dynasty. Even in the Campus Martius the spaces were limited and this is why Hadrian chose to build the tomb on the opposite bank of the Tiber, in the Horti Domitiae which had long belonged to the Imperial House.
To access the Mausoleum he built the Pons Aelius (Aelius Bridge) which was closely linked with the building and constituted its scenographic access.
The works began in 130 AD; in 134 the Aelius bridge was completed and inaugurated by the emperor himself. In 138, at the death of Hadrian, it had not yet been completed and was inaugurated by his successor Antoninus Pius.
The two Mausoleums have a similar structure, with a large square base that supported a cylindrical body, a scheme that we find in other famous Mausoleums such as that of Cecilia Metella on the Appian Way or that of the Plautii in Tivoli.
At the top of the Mausoleum of Augustus stood a statue of him in armor, probably similar to the one of Prima Porta. At the top of the Mausoleum of Hadrian was a large bronze Quadriga of the Sun, driven by the emperor himself depicted as Sol Invictus.
The Mausoleum of Hadrian changed its name and became Castel Sant’Angelo in 590 AD. after the legendary apparition of the Archangel Michael to Pope Saint Gregory the Great, who was leading a penitential procession during the terrible plague of those years. The Archangel cleaned his sword from blood and put it back in its sheath, a divine sign that the plague was over.
From that moment on, the Bridge became pons Sancti Angeli, and the Mausoleum, then transformed into a Castle, had the same name. Both were enclosed into the medieval and Renaissance fortifications.
At the end of the 15th century, the Mausoleum was definitively transformed into a fortress, digging a moat all around and covering it with bricks, adding battlements, altering the original structures with new rooms
. The popes created sumptuous apartments there, decorated by some of the greatest Renaissance artists. The pope took refuge in the Castle during the Sack of the Landsknechts of 1527.Inside that Renaissance shell, grandiose Roman structures have been preserved:
the lower vestibule, the helical ramp that leads up to the Burial Hall, preceded by a second Vestibule, ten meters higher than the enrance level.
The Hall pf the burial urns had three niches facing east, north and west. It was lit by window-tunnels, built in such a way as to capture the sun's rays only on the days of the Summer solstice. Even today, light enters from the windows and illuminates the three niches below, in which the imperial sarcophagi were placed.
These illuminations occur on the days of the summer solstice and had a precise symbolic meaning, linked to the imperial cult, to the dynastic succession and to the divinization after the death of Hadrian and the subsequent emperors.
As is explained in detail in the book by Marina De Franceschini: «Castel Sant’Angelo Mausoleum of Hadrian. Architecture and Light», which proposes a new and original reconstruction of the Mausoleum, without the tumulus and with a circular temple on top.