If the east bank of the Tiber dominated the pagan city, the west gradually took the lead in Christian Rome. For this change one man was primarily responsible. Saint Peter's name is as closely interwoven with the Transtiberine section as is that of Agrippa with the Pantheon or of Titus with his triumphal arch across the Sacred Way. And upon the 'rock' of Peter's name the Church of Rome was built.
Ancient tradition fixes the date of Peter's death as A.D. 67, near the end of Nero's reign; the place as the Circus of Gaius and Nero in the Vatican fields, where lay the gardens of the emperor's mother Agrippina; and the spot of his burial as a nearby cemetery.
When the first Christians met their deaths in Nero's circus, scapegoats suffering for the fire which the emperor himself had been accused of setting, an obelisk of red granite stood upon its spina, or central dividing wall. Caligula had brought it by ship from Heliopolis some twenty years before and set it up in the circus which Nero finished. Its age cannot be reckoned exactly as it has no inscription.
For more than fifteen centuries this obelisk stood where it had been set up by the emperor, while nearby, to the north, rose first an unknown shrine marking the grave of Peter, then the basilica which the Emperor Constantine built, and finally the great church which stands today. As buildings came and went and all the other obelisks of Rome fell from their ancient places, this one alone remained erect, an object of wonder, of admiration, and of conjecture.
The Middle Ages, which named the ruins of the circus where the obelisk stood 'the Palace of Nero', called the tall granite shaft 'Saint Peter's Needle', and believed that it contained the ashes of Julius Caesar in the globe on its top. The Mirabilia says of it:
'Within the Palace of Nero . . . is the basilica that is called Vatican, adorned with marvellous mosaic and ceiled with gold and glass. . . . There is also another temple that was Nero's Wardrobe, which is now called Saint Andrew; nigh whereunto is the memorial of Caesar, that is the Needle where his ashes nobly rest in his sarcophagus, to the intent that as in his lifetime the whole world lay subdued before him, even so in his death the same may lie beneath him for ever. The memorial was adorned in the lower part with tables of gilded brass, and fairly limned with Latin letters; and above at the ball, where he rests, it is decked with gold and precious stones, and there is it written:
" Caesar who once wast great as is the world,
Now in how small a cavern art thou closed."'
By the middle of the fifteenth century the old basilica which had seen the coronation of Charlemagne and many another emperor had become seriously weakened. Nicholas V proposed to rebuild it according to the original plan of a Latin cross, with three short arms and a longer one to form the nave. He died, however, when the work had been barely begun and it lapsed for fifty years. Then Julius II took up the project and commissioned Bramante to construct a new church according to the plan he had submitted--a Greek cross, having four equal arms, each covered with heavy barrel vaulting, their crossing crowned by a dome. 'I wish,' said Bramante, his mind upon the great buildings of the past he saw about him, 'to erect the dome of the Pantheon on the vaults of the temple of Peace' (the current name of the Basilica of Constantine). The cornerstone for this new structure was laid in 1506, a date which may fairly be called that of the present Saint Peter's beginning.
Unfortunately both Bramante and the pope died before many years and a succession of architects, including Raphael, changed Bramante's designs. Finally, in 1547, Michelangelo was put in charge. He revived the original idea of a Greek cross, but saw only the drum of the great dome complete before his death in 1564. His successor, Giacomo della Porta, completed it in accordance with his master's drawings, shaping the subtle curve which is at once the wonder and the despair of architects today.
It was in Giacomo della Porta's time that Sixtus V decided to have the obelisk moved from its comparatively inconspicuous place near the old sacristy south of the church to a commanding position in front. In 1586 Domenico Fontana supervised the moving, an engineering feat worthy of the energies of the Renaissance and one which created great excitement in Rome and comment throughout Europe. When it was completed, the eighty-two foot shaft, still unbroken, stood upright once more in front of the unfinished church. It was at this time that the globe on its top was replaced by the present cross; this globe, which contained no ashes, rests today in the Conservatori Museum, where one can see upon its surface the holes made by the shots of the soldiers of the Constable of Bourbon when they used it as target during the sack of Rome in 1527.
The new church, meanwhile, continued to grow slowly. In order to use it while work was going on, a partition had been run across it from side to side; for years the new dome towered above the old façade. From 1605 to 1615, when work had been completed as far as this wall, the old front part of the church was demolished and re-built in its present form. By this time the ruling pope, Paul V, had asked his architect, Carlo Maderna, who built the façade, to lengthen the nave, thereby giving more room for processions. As a result the lower part of the dome can be seen from the front only at a considerable distance. This defect has been partly remedied by the building of the present unencumbered approach to Saint Peter's. After the new façade was completed, the dividing wall was removed and the people of Rome saw their church as a whole for the first time. The new Saint Peter's was dedicated by Urban VIII on November 18, 1626, the traditional anniversary day of the dedication of the basilica built on the same site by Constantine in the fourth century. In the hundred and twenty years since the laying of the cornerstone in Bramante's day, twenty popes and almost as many architects had watched it rise step by step into one of the new wonders of the world.
It is not only the dome which can be called, with Ampère, a 'work of man that has something of the grandeur of the works of God'. An interior so limitless and varied is like a wide landscape; it cannot be seen as a whole; it has also an atmospheric colour of its own. The air, rather than the surfaces, of the immense enclosed space seems heavy with colour, though the walls are rich with subtle harmonies of marble which an emperor might have envied. And this air draws its varying colour from reflected light, changing from silver-grey to gold and rose and violet as the sunlight comes and goes and fades into the dusk.
But all was not finished with the completion of the church. Through the middle years of the seventeenth century Bernini created as its setting the Piazza of Saint Peter's, with its sweeping double colonnade enclosing the obelisk and the two fountains whose drifting clouds of spray and restless movement are subtly in harmony with the curving baroque porticos. No imperial building had a setting more satisfying than this; there comes to mind from ancient days only the vanished glory of the Forum of Trajan, 'beggaring description and never again to be imitated by mortal man'.
In Saint Peter's Piazza and the church beyond, which can contain more people than the Colosseum seated, the pilgrims of the world find a common home, as did the citizens of ancient Rome in their imperial city. The words of Sidonius Apollinaris, extolling Rome to his fellow Gaul, Eutropius, come inevitably to the mind: 'The city unique upon earth, where none but the barbarian and the slave is foreign.' But here there is no such qualification; this is a place of meeting, of reunion, of shared celebrations and worship for citizens of the Eternal City of the spirit, 'where there is neither bond nor free'.