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
Landsknechte during the
Sack of Rome (1527); the fortress was also the place in which
Benvenuto Cellini, while incarcerated due to charges of embezzlement, murder and sodomy, 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 (as described
above) 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;
Giordano Bruno, for example, was imprisoned there for six years. Other prisoners were the sculptor and goldsmith
Benvenuto Cellini and the magician and charlatan
Cagliostro. 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. During earlier times, the prison had another remarkable function.
Cornelis de Bruijn mentioned that when
Pope Clement X died in 1676, all prisoners with heavy sentences were transported to St. Angelo. Then, as soon as the papal seat became vacant, the local city council would release all prisoners from Rome's prisons except those that were locked in St. Angelo. This chain of events was, according to Cornelis, a custom every time the
pope died. == Fireworks ==