The Mausoleum of S. Constantia.
The same vintage scenes are represented in the beautiful mosaics with which the vault of the mausoleum is encrusted, and from this circumstance the monument received the erroneous name of the Temple of Bacchus, at the time of the Renaissance. There is no doubt that this is the tomb of the princess whose name it bears. Amianus Marcellinus, Book XXI., chapter i., says that the three daughters of Constantine—Helena, wife of Julian, Constantina, wife of Gallus Cæsar, and Constantia, who had vowed herself to chastity, and to the management of a congregation of virgins which she had established at S. Agnese—were all buried in the same place.
Plan of the Imperial Mausoleum.
The study of these two structures may help us greatly to explain the origin and purpose of the two rotundas which are known to have existed on the south side of S. Peter's, in the arena of Nero's circus. One of them, dedicated to S. Petronilla, was destroyed in the sixteenth century; the other, called the Church of S. Maria della Febbre, met with the same fate during the pontificate of Pius VI. Their exact situation in relation to the modern basilica is shown by the accompanying diagram.
Mention of the structure, with its classical denomination of "Mausileos," appears in the life of Stephen II. (a. d. 752). To fulfil a promise which he had made to Pepin, king of France, that the remains of Petronilla, who was believed to be the daughter of Peter, should be no longer exposed to barbaric profanations in their original resting-place on the Via Ardeatina, but put under the shelter of the Leonine walls near the remains of her supposed father, he selected one of these two rotundas, which became known as the "chapel of the kings of France." The early topographers of the Renaissance, ignorant of its history, gave a wrong name to the building, calling it the Temple of Apollo. That it was, however, of Christian origin, is proved not only by the fact that a temple could never have been built across the spina of the circus, and by the technical details of its construction, which show it to be a work of the end of the fourth or the beginning of the fifth century, but also by historical evidence. In 423 Honorius was buried in the mausoleum close by S. Peter's (juxta beati Petri apostoli atrium in mausoleo). In 451 the remains of the Emperor Theodosius II. were removed from Constantinople to the mausoleum ad apostolum Petrum. In 483 Basilius, prefect of the Prætorium, summoned the leaders of the clergy and of the laity to the mausoleum quod est apud beatissimum Petrum. A precious engraving by Bonanni, No. lxxiv. of his volume on the Vatican, represents the outside of one of the rotundas, the nearest to the obelisk of the circus. The architecture of the building, so similar to the tomb of S. Helena at Torre Pignattara, gives some conception of the enormous downfall of Roman art and civilization, when we compare it with the tombs of Augustus and Hadrian.
The discovery of the imperial graves which filled the two rotundas did not take place at one and the same time. Their profanation and robbery was accomplished in various stages, by various persons; and so little has been said or written about them, that only in these last years has de Rossi been able to reconstruct in its entirety this chapter in the history of the destruction of Rome.