Castel Sant'Angelo is a towering cylindrical castle, initially commissioned by the Roman Emperor Hadrian as a mausoleum for himself and his family. The building was later used by the popes as a fortress and castle, and is now a museum. The castle was once the tallest building in Rome.
The tomb of the Roman emperor Hadrian was erected on the right bank of the Tiber, between 134 and 139 AD. Originally the mausoleum was a decorated cylinder, with a garden top and golden quadriga. Hadrian's ashes were placed here a year after his death in Baiae in 138, together with those of his wife Sabina, and his first adopted son, Lucius Aelius, who also died in 138. Following this, the remains of succeeding emperors were also placed here, the last recorded deposition being Caracalla in 217. The urns containing these ashes were probably placed in what is now known as the Treasury room deep within the building. Hadrian also built the Pons Aelius facing straight onto the mausoleum. It still provides a scenic approach from the center of Rome and the left bank of the Tiber, and is renowned for the Baroque additions of statues of angels holding aloft instruments of the Passion of Christ.
Much of the tomb contents and decorations have been lost since the building's conversion to a military fortress in 401 and its subsequent inclusion in the Aurelian Walls by Flavius Augustus Honorius. The urns and ashes were scattered by Visigoth looters during Alaric's sacking of Rome in 410, and the original decorative bronze and stone statuary were thrown down upon the attacking Goths when they besieged Rome in 537, as recounted by Procopius. An unusual survivor, however, is the capstone of a funerary urn (probably that of Hadrian), which made its way to Saint Peter's Basilica, covered the tomb of Otto II and later was incorporated into a massive Renaissance baptistery.
Legend holds that the Archangel Michael appeared atop the mausoleum, sheathing his sword as a sign of the end of the plague of 590, thus lending the castle its present name.
The popes converted the structure into a castle, beginning in the 14th century; Pope Nicholas III connected the castle to St Peter's Basilica by a covered fortified corridor called the Passetto di Borgo. The fortress was the refuge of Pope Clement VII from the siege of Charles V's soldiers during the Sack of Rome (1527), in which Benvenuto Cellini describes strolling the ramparts and shooting enemy soldiers.
Leo X built a chapel with a Madonna by Raffaello da Montelupo. In 1536 Montelupo also created a marble statue of Saint Michael holding his sword after the 590 plague to surmount the Castel. Later Paul III built a rich apartment, to ensure that in any future siege the pope had an appropriate place to stay.
Montelupo's statue was replaced by a bronze statue of the same subject, executed by the Flemish sculptor Peter Anton von Verschaffelt, in 1753. Verschaffelt's is still in place and Montelupo's can be seen in an open court in the interior of the Castle.
The Papal state also used Sant'Angelo as a prison. Executions were performed in the small inner courtyard. As a prison, it was also the setting for the third act of Giacomo Puccini's 1900 opera Tosca; the eponymous heroine leaps to her death from the Castel's ramparts.
Decommissioned in 1901, the castle is now a museum, the Museo Nazionale di Castel Sant'Angelo.
References:The Basilica of Santa Maria in Trastevere is one of the oldest churches of Rome. The basic floor plan and wall structure of the church date back to the 340s, and much of the structure to 1140-43. The first sanctuary was built in 221 and 227 by Pope Callixtus I and later completed by Pope Julius I.
The inscription on the episcopal throne states that this is the first church in Rome dedicated to Mary, mother of Jesus, although some claim that privilege belongs to the Basilica di Santa Maria Maggiore. A Christian house-church was founded here about 220 by Pope Saint Callixtus I (217-222) on the site of the Taberna meritoria, a refuge for retired soldiers. The area was made available for Christian use by Emperor Alexander Severus when he settled a dispute between the Christians and tavern-keepers.
The church underwent two restorations in the fifth and eighth centuries and in 1140-43 it was re-erected on its old foundations under Pope Innocent II.