Today I'll tell you about the Ponte Sant'Angelo ("Bridge of the Holy Angel"), the bridge that ties the city's center to Castel Sant'Angelo ("Castle of the Holy Angel").
Originally, both the bridge and the "castle" were built by Imperator Hadrian.
What we now refer to as a castle, was a mausoleum, a monumental tomb that Hadrian built for himself and his relatives. Also the bridge was built by him, to give easy access to his funerary monument.
Later in the centuries, the original mausoleum was converted to a fortress for the defense of the city, then a prison, a set for the public executions, later the summer residence of the Pope.
The bridge remained a bridge, but it faced a good deal of changes too, as the building that it guarded changed with time.
During the Middle Ages, with the advent of Christianity, Rome turned into a city of pilgrimage and this bridge was a favoured route to reach the church of Saint Peter.
For this reason, it was referred to as "Bridge of Saint Peter".
The name "Holy Angel" refers to a vision of Pope Gregory I, when he saw the Archangel Michael cleaning his sword from blood and placing it back in its sheat on top of the castle, during a procession to pray for the end of a plague that was afflicting Rome.
As after the procession the plague ended, a statue of the angel was erected on top of the castle.
Two little chapels, dedicated to Mary Magdalene and to the Innocents, decorated the entrance to the bridge, to commemorate an accident occurring during the Jubilee of 1450, when 172 pilgrims died because of the huge crowd. They were commissioned by Pope Nicholas V, who witnessed the desaster.
As in 1527 Pope Clemens VII noticed how the chapels sheltered the invaders during the sack of Rome, he ordered their destruction and in 1535 they were replaced by the monumental statues of Saint Paul (built by Paolo Romano) and Saint Peter (by Lorenzetto), the Patron Saints of Rome.
The two Saints were placed there as "guardians" to the route to Vatican.
Two inscriptions could be read under the two statues: "Hinc humilibus venia" for Saint Peter and "Hinc retributio superbis" for Saint Paul. Read together, they mean something along the lines of "From this point onward, mercy to the humble, retribution to the proud": an encouragement for the pilgrims (the keys to Heaven of Saint Peter) but a threat to the invaders (the sword of Saint Paul, originally a soldier).
In 1668, Pope Clemens IX decided to fix the bridge and commissioned the glorious Bernini with the task.
Faithful to its favoured route to Saint Peter and mindful of its gruesome story, the pope decided to highlight its significance as a Via Crucis by placing a series of angels holding the Instruments of Passion.
Bernini planned the restoration and the reorganization of the bridge's structure, and left the execution of the Angels, based on his drawings, to his students.
Besides the Instruments, all the Angels sport an inscription based on verses from the Old Testament, excerptions that refer to the advent of Jesus Christ and his Passion.
The most of them come from Psalms and the books of Prophets to stress their "foretelling" value and to suggest sources of meditation to the pilgrims.
The first angel to be spotted is the angel with the column: Tronus meus in Columna, "My throne is upon a column" (Sirach 24:4)
Following the episode of Jesus' Passion, the scourge: In flagella paratus sum, "I am ready for the scourge" (Psalm 37:18)
The crown of thorns: In aerumna mea dum configitur spina, "The thorn is fastened upon me" (Psalm 31:4)
The Veronica's veil: Respice faciem Christi tui, "Look upon the face of your Christ" (Psalm 84:9)
The the garment and dice: Super vestimentum meum miserunt sortem, "For my clothing they cast lots" (Psalm 22:18)
Jesus is finally given the cross: Cuius principatus super humerum eius, "Dominion rests on his shoulders" (Isaiah 9:6)
Once he reached the Golgotha, he met the nails: Aspicient ad me quem confixerunt, "They will look upon me whom they have pierced" (Zechariah 12:10)
The INRI subscription: Regnavit a ligno deus, "God has reigned from the tree" (sixth-century hymn)
Right before his death, Jesus is given a wine-soaked sponge: Potaverunt me aceto, "They gave me vinegar to drink" (Psalm 69:21)
Finally, to ascertain his death, Longinus wounded his chest with his spear: Vulnerasti cor meum, "You have ravished my heart" (Song of Solomon 4:9)
...In case you feel like reading more on the subject, I link you this page from BeliefNet, from where I took the inscriptions and the translations.
--Of course this story is not over yet.
To say the truth, Bernini sculpted two Angels of the series, the "crown of thorns" and the "INRI subscription", but it's said that Pope Clement IX was so fond of them that he kept both statues for himself, commissioning two of Bernini's students, Paolo Naldini and Giulio Cartari, to make copies of them to place on the bridge.
Fortunately both statues are still preserved and visible in the church of Sant'Andrea delle Fratte, where they were moved to in 1729.