Skip to content

Castle of the Week 129 - Castel Sant’Angelo


A Mausoleum of Emperors

Castel Sant’Angelo was originally a mausoleum, whose construction was begun by the Roman Emperor Hadrian on the right bank of the Tiber River in 123 A.D. on the outskirts of Rome in Domitia’s gardens. The mausoleum was completed by Hadrian’s successor, Antonius Pius, between 135 and 139. The building was designed with a square base 89 meters wide with a colonnaded cylinder of 64 meters in diameter resting on it whose Roman masonry is clearly visible in the lower section of the castle’s keep. Atop the cylinder, was an earthen tumulus topped by a golden quadriga and a statue of the sun god with the likeness of Hadrian. Emperor Hadrian’s ashes were placed in what is now known as the Treasury Room, deep within building. The ashes of his wife and son were placed with him later along with the ashes of all the Roman emperors up until Caracalla’s death in 217 A.D. Accompanying the mausoleum, a new bridge was built to provide scenic, direct access through the center of Rome, the Pons Aelius, which was later renamed Pont Sant’Angelo.

Military Use and Medieval History

Between 270 and 275 A.D., Hadrian’s mausoleum was fortified and integrated into the new Aurelian Walls to defend the northern entrance of Rome, which had swelled to a larger size since Hadrian’s time. From that point onward, the mausoleum was gradually fortified further. In 401 A.D., the building was fully converted to fortress use by order of Flavius Augustus Honorius and served as the nucleus of resistance against the barbarian assaults on the city. Eventually, the urns were shattered and the ashes scattered by Alaric’s Visigoth looters during the sack of Rome in 410. The bronze and stone statuary was thrown down by the Goths in 537, as recounted by Procopius. During the devastating plague of 590, Pope Gregory led a procession to plead for the end and claimed to have seen the apparition of St. Michael the Archangel appear atop the mausoleum and sheath his sword, symbolizing the end of the epidemic. The castle and bridge were to be renamed in the 7th century after the Archangel. In the proceeding centuries of Italian city states the castle changed hands of many noble families with a tower added in the 9th century and more battlements constructed in the 11th century.

In 1277 the fortress was acquired by the papacy who utilized the building as a refuge from dangerous sieges for the Pope formerly held much greater political power and more cynical men would exhaust the papal army, sack Rome, and hold the Pope for ransom until he gave them titles and divine authority to sack a kingdom as was the case with Robert the Weasel in the 11th century among others. Shortly after the acquisition of the fortress, a secret corridor was built by Nicholas III, known as the Passetto di Borgo, which connects Castel Sant’Angelo with the Vatican. The passage fulfilled its purpose when Pope Alexander VI fled the invading Charles VII of France in 1494 and when Pope Clement VII sprinted its length to take refuge while Charles de Bourbon’s army crushed the Swiss Guard defending St. Peter’s Basilica in 1527.

Renaissance and Beyond

During the Renaissance, the papacy built additions and decorated the castle and bridge. A chapel was added by Leo X. The structure of the castle can be divided into levels of floors. The first floor contains the start of a 400 foot long winding corridor ramp built by the Romans that follows along the keep’s wall. The first floor also contains a chapel and hospital. The second floor contains store rooms for wheat and oil, a diametric stairwell, and many horrible prison cells that formerly contained many political and religious and irreligious prisoners who would be hanged and/or beheaded with their remains displayed on the bridge. The third floor is the main military floor with barracks, courts, halls, and two courtyards where the executions took place. The fourth floor contains the papal apartment complex, the historical armory, and the loggia of Julius II. The fifth floor contains the Treasury--Sala del Tesoro where the papacy’s treasures were stored and the urns formerly located, the castle library, halls, Castellano’s apartment built in the 18th century above the loggia, and Cagliostro’s Room—the room of the famous 18th century alchemist, pharmacist, physician, and traveler after his capture by the Inquisition. Even in this fortress, the pontiffs were well housed with beautiful rooms and halls decorated with frescoes painted by Giulio Romano, Perin del Vaga and others of Raphael’s art school. The top floor has a hall of columns and a panoramic terrace with a bronze statue of the Archangel, cast by Pieter Verschaffelt in the 18th century to replace an earlier marble version sculpted by Raffaello da Montelupo in the 1500s. Lovers of opera will know that it is from here that Puccini’s Tosca leapt to her death.


Surprisingly, an original capstone of a funerary urn contained in the mausoleum survived Rome’s turbulent history and was recycled in Saint Peter’s Basilica in its massive Renaissance baptistery. Giorgio Vasari wrote in the 16th century how the new churches built for the use of the Christians caused the destruction of the remaining Roman idol statues and how the stone columns from the tomb of Hadrian and décor from other old Roman buildings were used in order to ennoble and decorate Saint Peter’s Basilica. In 1535 statues of Saint Peter and Saint Paul were erected on the bridge with statues representing Adam, Noah, Abraham, and Moses added shortly afterwards. In 1669 Pope Clement IX commissioned Bernini to sculpt angels as replacements. Not only was the castle decorated during this period, but it was also modernized to the times with cannon emplacements created in the towers of the walls and additional ramparts constructed.

The Castle Today

After the establishment of the unified Italian State, the structure was utilized as a military barrack until its decommission in 1901, when it was converted for museum use as the Museo Nazionale di Castel Sant’Angelo. As a museum, it showcases many collections of ceramic artworks, precious paintings, sculptures, and the armament of Italian soldiers and the garrison throughout the castle’s history. For over 1,000 years, the castle was militarily strategic for controlling Rome and defending Popes. The second largest construction in Rome after the Coliseum, Castel Sant’Angelo looms over the Tiber, guarding the eternal city.



Author’s Note: I have been to Rome once before and lament not being able to tour inside Castel Sant’Angelo as it was closed for restoration, preservative cleaning purposes, and archaeological exploration at the time. Wondering the streets and buildings of Roma and the Vatican State, it is easy to miss the castle, but once you near the river, the castle presides inescapably along the skyline. My experience with the castle was limited to leisurely strolling the cobblestone streets along its perimeter and gardens while watching a glorious sunset from the Ponte Sant'Angelo as the castle’s terracotta bricks became most pronounced and clouds bloomed fuchsia on the Tiber. Roma is a warm city, even in February.

Write-up by Sir Hugh.

Special Thanks Goes To:

Wikimedia Commons (Main, 1, 2)

Google Earth

Recommended Links:

Website of the Museum
The translated Website of the Museum contains the castle’s history up until the 500s, information about its exhibits, diagrams of the castle and predicted mausoleum, and floor plans.
ItalyGuides
This site has some wonderful panoramic views of the castle’s surroundings.
The ancient history of Hadrian's Mausoleum


Previous Index Next

*) denotes a former staff member.