T HE heart of ancient Rome lay on the east or left bank of the Tiber, where the city had first begun to expand from the Palatine settlement. As it spread out over wider areas it took in the west or right bank of the river, including a district that has always held itself aloof. The name of this section, Regio Transtiberina, Region across the Tiber, survives today in that of its southern part, Trastevere, a crowded, colourful, still slightly medieval neighbourhood, whose residents long considered themselves more nearly pure-blooded descendants of the ancient Romans than those of any other part of the city.
Through almost the entire length of the region runs 'the long ridge of the Janiculum', which Martial praised more than eighteen hundred years ago. From this, the highest hill of Rome, never reckoned among the immortal seven, wide sheltered reaches look down on the hills, and the flat summit, gently swelling, enjoys to the full a clearer sky, and, when mist shrouds the winding vales, alone shines with its own brightness. . . . On this side may you see the seven sovereign hills and take the measure of all Rome, the Alban hills and Tusculan too, and every cool retreat nestling near the city.'
The northern and southern parts of Transtiberine Rome, throughout imperial days, formed the fourteenth region of the city; its separation into two distinct parts came about through later redistricting. The whole section, only a small part of which was enclosed within Aurelian's wall, was characterized by a sharply contrasting mixture of working-class homes, imperial and patrician gardens, and circuses for games and sports. The gardens which Julius Caesar willed to the people of Rome were in the southern section; the site of the immense tomb which Hadrian built for himself and his successors was probably part of an imperial garden in the northern part. By that time little space was available nearer the centre of the city, and the prudent emperor had no wish to copy the folly of Nero by seizing private property.
Hadrian began the tomb several years before his death in A.D. 138, but it was finished by his successor. Its outer walls are of concrete and stone, once faced with marble; within, is a network of brick walls, ancient and medieval and renaissance. The tomb has been one of the most continuously used and therefore one of the most altered of Roman monuments. Beneath the accumulations of centuries, however, the plan is still clear--a circular core rising from a square podium, later surrounded by fortifications shaped roughly like a five-pointed star. The greatest change in its appearance in recent years has been the freeing of these walls from later buildings which had crept over them.
The last Roman emperor known to have been buried here was Caracalla, who died in A.D. 217. Aurelian (270-275) incorporated the tomb in the city's fortifications; in the bloody period of the sixth century it served as one of the chief fortresses of the Byzantine general, Belisarius, after he had captured the city from the Goths. The fighting was especially severe here when the Goths attempted to recapture Rome in 537, as the contemporary Byzantine historian, Procopius, records:
'The tomb of the Roman Emperor Hadrian stands outside the Aurelian Gate, removed about a stone's throw from the fortifications, a very noteworthy sight. For it is made of Parian marble and the stones fit closely one upon the other, having nothing at all between them. And it has four sides which are all equal, each being about a stone's throw in length, while their height exceeds that of the city wall; and above there are statues of the same marble, representing men and horses, of wonderful workmanship. But since this tomb seemed to the men of ancient times a fortress threatening the city, they enclosed it by two walls, which extend to it from the circuit-wall, and thus made it a part of the wall. And, indeed, it gives the appearance of a high tower built as a bulwark before the gate there.'
The Goths pressed so close to the walls that the defenders were unable to use their ordinary weapons. 'For a short time', Procopius continues, 'consternation fell upon the Romans, who knew not what means of defence they should employ to save themselves, but afterwards by common agreement they broke in pieces the most of the statues, which were very large, and taking up great numbers of stones thus secured, threw them with both hands down upon the heads of the enemy, who gave way before this shower of missiles.'
During the Middle Ages the tomb went by various names, such as 'House' or 'Prison' of Theodoric the Ostrogoth, and 'Castle of Crescentius', referring to its defence by Giovanni Crescentius, a Roman noble, against the Holy Roman Emperor Otto III. The early version of the Mirabilia refers to it under the heading 'Castle of Crescentius', saying:
'There is a castle that was the temple of Hadrian . . . a temple built up, of marvellous greatness and beauty; the which was all covered with stones and adorned with divers histories, and fenced with brazen railings round about, with golden peacocks and a bull, of the which peacocks two were those that are at the Basin of the Parvise [the atrium of old Saint Peter's]. At the four sides of the temple were four horses of gilded brass, and in every face were brazen gates.'
The name by which it is still most widely known, the Castle of Sant' Angelo, or Holy Angel, comes from an early legend, according to which Pope Gregory the Great, while conducting a procession to pray for the ending of the plague in Rome in the year 590, beheld the Archangel Michael sheathing his sword above the castle as a token that the pestilence would cease. A fourteenth-century version of the Mirabilia notes that this 'is called the Angel's Castle'. The bronze angel which crowns the Castello today replaced one of marble in 1752. There is some uncertainty as to when the first angel was erected.
From the late fourteenth century the castle was the special fortress of the popes, who connected it with the Vatican by a covered passage for use in emergency. It has endured many sieges since then, the most terrible being that by the German and Spanish forces of Charles V in 1527. This was the siege in which Benvenuto Cellini, one of its defenders, declared that he himself had shot the Constable de Bourbon, leader of Charles' forces. Early in the twentieth century this ancient tomb and fortress, which had meanwhile been put to use as prison, as barracks, and as storehouse for powder, finally became a museum.
The Angel's Castle has a long history in art, fostered, no doubt, by its nearness to Saint Peter's. It occupied a prominent place in every medieval and renaissance plan, and was one of the first monuments to symbolize the city. As such a symbol it appears in the foreground of one of the earliest medieval views of Rome--the dim, almost unrecognizable, group of conventionalized 'marvels' which accompanies the figure of Saint Mark in a thirteenth-century vault of the upper church of Saint Francis at Assisi. In this time-worn fresco, sometimes attributed to Cimabue, the castle seems to have an angel on its summit. An account of a miracle during the plague of 1348 says that the angel's statue bowed to the Madonna, carried in a procession across the Angel-bridge.
When the new Saint Peter's was completed in the seventeenth century, the contrast of its soaring dome with the grim and heavy mass of the castle created a new composition, especially beloved by artists. The old views of the castle from downstream were not forgotten, but that from above, showing both the castle and Saint Peter's, was spread far and wide by engravings.
A note of festivity runs through pictures of the castle too. Through most of four centuries it was the setting for the most magnificent display of fireworks in a city famed, then as now, for the beauty of such spectacles. This was la girandola, 'the revolving one', named from the profusion of its radiating rockets and revolving wheels.
The first mention of this display is in 1481, though it may have been shown earlier. It was held on various occasions, such as Easter Monday, the Festival of Saints Peter and Paul at the end of June, the election or coronation of a pope, or on papal anniversaries. Tradition has it that some of the effects were designed by Michelangelo.
From the time of the Roman Republic of 1798-1799 until after the city became the capital of United Italy in 1870, the girandola was often shown at other places, such as the Pincian hill or the church of San Pietro in Montorio on the Janiculum. For a few years after 1872 the display was again centred at the castle, though more rarely. Soon, however, the jarring caused by the powder charges damaged some of its frescoed rooms, and the fireworks were regarded as too hazardous for the ancient building. The famous spectacle was held here for the last time in 1887.