Old Rome Part 12

The figure of Marcus Aurelius on horseback, accompanying a long train of spoil taken from the German tribes, and a long series of battles, conflagrations of villages and towns, conferences with the enemy's generals follow, and the first campaign ends at a point near the centre of the column, with a procession of trophies and spoils of war, in the midst of which a figure of Victory inscribes the triumph on a shield.

Over this figure of Victory begins the history of the second campaign, in which four battles are represented, and various military scenes, as the crossing of the Danube in boats, the thanksgiving sacrifices after victory, the emperor addressing his army, captures of women and children, and finally a long train of captives and spoils led off in triumph. This great marble history is after the model of that on Trajan's Column. The style of execution is, however, somewhat different: the figures stand out much more from the surface, are more roughly cut, and have a heavier and stiffer look, resembling that of the reliefs upon the Arch of Severus, and the base of the Pillar of Antoninus Pius.

The column is called in all ancient writings Columna Antonini, which may apply to either of the Antonines. But it is perfectly evident from spiral reliefs, representing the frequent crossings of the Danube, and especially from that recording the incident of the sudden storm which extricated the Roman army from their difficulties, that the German wars of Marcus Aurelius are the subject commemorated.

Aurelius Victor and Julius Capitolinus state that temples, columns and priesthoods, were dedicated to this emperor after his death, and some inscriptions discovered in 1777 in the Piazza Colonna establish the conclusion that this pillar was erected in his honour beyond doubt. These inscriptions, now in the Gallery of Inscriptions in the Vatican, contain a pet.i.tion from Adrastus, a freedman of Septimius Severus, and custodian of the Pillar of Marcus Aurelius, addressed to the Emperor Severus requesting leave to have the miserable hut (cannaba) in which he lived changed into a habitable house (solarium) for himself and his heirs, and also the decree of the emperor, giving the permission and a.s.signing materials and a site.

The pet.i.tion was presented immediately on the accession of Severus, and the decree is dated in the consulship of Falco and Clarus, A.D. 193, two months after the emperor had taken possession of the palace. In this inscription the pillar is called the Columna Centenaria, and exact measurements of the shaft have shown that it is just one hundred Roman feet in height, including the base and capital.[99]

The bronze statue of Marcus Aurelius, which stood on the summit, was probably carried off by the Byzantine emperor, Constans II., to Syracuse, and was there taken by the Saracens from him, and conveyed to Alexandria with the rest of the plunder he had stripped from the buildings of Rome.

To distinguish this column from the above-mentioned Pillar of Antoninus Pius, it is called in some of the legal doc.u.ments of the tenth century "Columpna major Antonina." As recorded in the inscription on the modern base, it was much injured by lightning in the fourteenth century, and restored by Sixtus V.

[Sidenote: Piazza Navona.]

The Piazza Navona was formerly a stadium, not a circus. The strongest evidence we have in favour of this rests on the shape of the piazza and of the ruins. One of the essential parts of a circus, the spina, is entirely wanting, and the end from which the runners started is at right angles to the longer sides, while in a circus, as in the case of the Circus of Maxentius, the carceres always stood in a slanting direction across the course, in order to equalise the distances round the spina.

The obelisk, which now stands in the centre of the piazza was brought by Innocent X. from the Circus of Maxentius on the Appian Road. The Circus of Maxentius was not, however, its original site, for the hieroglyphics are of Roman execution and contain the name of Domitian.

[Sidenote: Mausoleum of Augustus.]

The northern part of the Campus Martius, between the Via del Ripetta and the Pincian Hill, contained only one great building of which we have any knowledge. This was the Mausoleum of Augustus, the ruins of which are now buried under the Teatro Correa, and are approached by a narrow entry leading out of the Via dei Pontefici. All that can now be seen of the shapeless ma.s.s which this once stately building presents, is a small part of the cylindrical brickwork bas.e.m.e.nt on the left of the entrance to the Teatro Correa, and another fragment of the same at the back of the Church of S. Rocco. The proofs that these are the remains of the Mausoleum of Augustus are quite indisputable. Suetonius places it between the Tiber and the Flaminian Road, and Strabo speaks of it as standing near the bank of the river, descriptions which, though they are not very definite, agree with the site of the Teatro Correa sufficiently. Complete certainty is, however, afforded by the inscriptions which have been found on the site of the Ustrina Caesarum, where the bodies were burnt before burial. These were found near the Corso, between the Via degli Otto Cantoni and the Via dei Pontefici, a spot answering to Strabo's notice of the site of the Ustrina as standing in the middle of the Campus, which is here narrowed by the approach of the Pincian Hill towards the river.

Augustus had built this magnificent tomb in his sixth consulship (B.C.

28). At that time the course of the Flaminian Road through the Campus was lined with the tombs of many eminent Roman statesmen and public characters, which have all, with the exception of the insignificant Tomb of Bibulus, totally disappeared. The modern city has entirely effaced all traces of these, but we may in all probability suppose that the Flaminian road presented no less striking a spectacle in the days of Augustus than the Appian, which we are accustomed to regard as the great burying-place of Rome.

The name mausoleum was apparently given to this tomb if not immediately, yet soon after its completion, not from any resemblance in the plan of the building of the famous monument of the Halicarna.s.sian queen, which differed entirely in shape and design, but because the expression mausoleum had already become a name used to designate any tomb of colossal proportions. The Mausoleum of Halicarna.s.sus was a rectangular building surrounded with a colonnade, while the Tomb of Augustus was cylindrical and ornamented with deep niches. Strabo gives the following description of the latter monument: "The most remarkable of all the tombs in the Campus is that called the Mausoleum, which consists of a huge mound of earth raised upon a lofty base of white marble near the river bank, and planted to the summit with evergreen trees. Upon the top is a bronze statue of Caesar Augustus, and under the mound are the burial-places of Augustus and his family and friends, while behind it is a s.p.a.cious wood containing admirably designed walks. In the middle of the Campus is the enclosure he made for burning the corpses, also of white marble, surrounded by an iron railing, and planted with poplar-trees."[100]

The mound of earth here described by Strabo was probably of a conical shape, and the trees were planted on terraced ledges. The ma.s.s of the building was cylindrical, like the central portions of Hadrian's Mausoleum, and of the tombs of Plautius and Caecilia Metella, and was supported upon a square bas.e.m.e.nt which is now entirely buried beneath the level of the ground. The exterior of the cylindrical part was relieved by large niches which doubtless contained statues, and broke the otherwise heavy uniformity of the surface. At the entrance were the bronze pillars which Augustus had ordered to be erected after his death, on which was engraved a catalogue of the acts of his reign. We now possess a fragment of a copy of this interesting doc.u.ment in the famous Monumentum Ancyranum, found at Ancyra in the vestibule of a Temple of Augustus. Besides these pillars two obelisks stood in front of the entrance door, one of which is now placed in the Piazza of S. Maria Maggiore, while the other stands between the statues of the Dioscuri on the Quirinal. These obelisks were not, however, placed there at the time when the tomb was first built, but at a later period of the empire. The entrance fronted towards the city, i.e., to the south, near the apse of the Church of S. Rocco, and appears to have had a portico with columns, the traces of which are still left.

The interior was formed by ma.s.sive concentric walls, the s.p.a.ces between which were vaulted and divided into cells for the deposit of the urns containing the ashes of the ill.u.s.trious dead. A great alabaster vase found near the Mausoleum in 1777, and placed in the Vatican Museum, was probably one of these. We know from various pa.s.sages of Roman authors that the first burial which took place here was that of the young Marcellus, the favourite nephew of Augustus, who died at Baiae[101] in B.C. 23, and the last, that of the Emperor Nerva in A.D. 98. Trajan was buried under his column. The Mausoleum of Hadrian became the Imperial tomb in A.D.

138.[102] During the 160 years which intervened, the ashes of Agrippa, Octavia, the mother of Marcellus, Drusus, Caius and Lucius, Augustus himself and Livia, Germanicus, Drusus, son of Tiberius, the elder Agrippina, Tiberius, Antonia (wife of L. Domitius), Claudius and Britannicus were deposited here. Besides these there must have been a great number of other friends and relations of the Imperial family buried here. Only one of all the inscriptions recording these burials is now extant. It is engraved on a pedestal, which bore the urn where the ashes of the elder Agrippina, the wife of Germanicus and mother of Caligula, lay. In the inscription on this pedestal Caligula is called Augustus, showing that the burial took place after his accession, in accordance with the account of Agrippina's banishment by Tiberius. The pedestal was hollowed out and used in the Middle Ages as a measure for corn, and is still inscribed with the words RUGITELLA DI GRANO. It may now be seen in the courtyard of the Conservator's Palace on the Capitol. At the same time, and at a spot between the Mausoleum and the Corso were found six cippi of travertine, recording the burning of the bodies of four of the children of Germanicus, Tiberius Caesar, Caius Caesar, Livilla, and one whose name is erased. The remaining two cippi record the burning of the bodies of a son of Drusus, and of one of the Flavian family. It is evident that these belonged to the Ustrina Caesarum, a place described by Strabo, as quoted above, where the corpses of the dead were burnt and the formal ceremony of collecting the bones took place. The cippi may still be seen in the Vatican Museum.

The Mausoleum remained closed after Nerva's burial until the capture of Rome by Alaric in A.D. 409, when the Goths broke it open in their search for treasure, and scattered the ashes of the Caesars to the winds. It was then probably that the alabaster vase mentioned above was removed from the Mausoleum and carried to the Ustrina where it was found.

In the 12th century the Mausoleum suffered the fate of all the other great buildings of Rome. It became a castle of the Colonna family, and bore the name Augusta. The mound of earth was then probably removed, and a stone or brick tower built in its place. Previously to this, the statue of Augustus, with the bronze decorations of the Pantheon and Forum of Trajan, had probably been carried to Syracuse by Constans, and thence to Alexandria by the Saracens.

The building might, however, still, like the tomb of Hadrian, have long defied the attacks of time, had not the Romans themselves, in the commotions of 1167, demolished the Colonna Castle, and with it the greater part of the walls upon which it was built. Two hundred years later, the body of the last of the Tribunes, Cola di Rienzi, was burned by the Jews before the Mausoleum.[103] At that time the spot was called Campo d'Austa from the ancient site of the Ustrina. The interior chambers seem to have been entirely demolished in the 15th century, and only the exterior wall left. Poggio, the Florentine, describes the building as used in his time (1440) for a vineyard, and before that date its shape was completely changed by the falling in of the vaulting of the interior, so that it presented the appearance of an amphitheatre instead of a lofty conical building. In Donatis' book (1638), it is represented as a funnel-shaped ruin with a garden on the sloping sides of the interior. Much information might doubtless be gained by well-directed excavations, which have apparently never been undertaken on account of the present occupation of the ruin as a circus in winter and a theatre (the Teatro Correa) in summer.

[Sidenote: Muro Torto.]

Beyond the Porta del Popolo on the edge of the Pincian hill, there is a very ancient piece of wall, faced in the style called opus reticulatum, which is made of small diamond-shaped blocks of tufa set in the surface of a ma.s.s of concrete. These blocks are driven into the concrete before the lime has dried and set. This ruin, which is called the Muro Torto, is often spoken of as having been a part of the house of Sylla but I do not know upon what authority. It may have formed a part of the substructions of some of the private buildings on the Pincian, previous to the time of Aurelian, who incorporated it in his wall. Near the angle of the wall where it turns sharply to the south is a point at which the brickwork leans in great ma.s.ses considerably out of the perpendicular, whence the name of Muro Torto. Procopius speaks of this as having been in the same state long before his time, and calls it the broken wall.

[Sidenote: Pons aelius.]

Pa.s.sing along the bank of the Tiber by the Via Ripetta from the Porta del Popolo we come to the bridge of S. Angelo (Pons aelius) which crosses the river close to the Castle of S. Angelo, anciently the Mausoleum of Hadrian. This bridge was built by the Emperor Hadrian at the same time with his Mausoleum. The anonymous writer of the Einsiedlen MS. gives an inscription which in his time remained upon the bridge a.s.signing its erection to the nineteenth tribuneship and third consulship of Hadrian, which indicates the year A.D. 135, and in confirmation of this Nardini gives a medal of Hadrian which dates from his third consulship, and has on the obverse a representation of this bridge. The name Pons aelius, given to it by Dion Ca.s.sius in his account of Hadrian's funeral, was probably derived either from Hadrian's praenomen aelius, or from the name of his son aelius Caesar whose burial was the first which took place in the Mausoleum.

The piers of the bridge are ancient, but the upper parts have been rebuilt.

[Sidenote: Mausoleum of Hadrian.]

The Mausoleum of Hadrian owes its preservation entirely to the peculiar fitness of the site and shape for the purpose of a fortress which it has served since the time of Belisarius. Had it not been thus made serviceable to the turbulent spirit of the mediaeval Romans, the same hands which stripped the great pile of its marble facing, and, after hurling the statues with which it was adorned into the moat, allowed them to lie there in oblivion, would have torn asunder and carried away the whole ma.s.s to furnish materials for the palaces and stables of their ferocious and ignorant n.o.bles. The original form of this colossal mausoleum is now greatly changed by the modern buildings which have been piled upon it, by the addition of the corbels round its upper part, and by the loss of the exterior facing of marble, so that the ancient appearance can be only conjecturally restored. The remaining ancient part consists of a square bas.e.m.e.nt of concrete and travertine blocks, the sides of which measured ninety-five yards surmounted by an enormous cylindrical structure of travertine seventy yards in diameter and seventy-five feet high. Procopius tells us that this was cased in Parian marble, and that upon the summit stood a number of splendid marble statues of men and horses.[104] There are several other tombs in Italy constructed upon the same plan with a cylindrical tower placed upon a square base. Two of these are upon the Appian road about three miles from Rome, the celebrated Tomb of Caecilia Metella, and that of the Servilii, and belong to the Republican Era. Two others are of the Augustan Age, the tomb of the Plautii at Ponte Lucano, near Tivoli, and the beautiful monument of Munatius Plancus, near Gaeta.

Hadrian's design was not therefore by any means a new one, as we might have expected in the case of an emperor who was himself an architect, and proud of his artistic designs.

It is plain from the history of Procopius that the statues of men and horses which he describes were upon the top of the building. For the defenders of the mausoleum against the army of Vitiges being hard pressed by the approach of the Goths under shelter of a testudo, in their despair seized these statues and hurled them upon the heads of their a.s.sailants, thus breaking down the testudines and repelling the attack. Of the exact order in which they were arranged we have no evidence. Tradition a.s.serts that the twenty-four Corinthian columns destroyed by fire in the Basilica of St. Paul in 1823 formerly belonged to the Mausoleum of Hadrian, and that they were removed by Honorius.[105] A comparison of this tradition with a pa.s.sage of Herodian, in which he says that the ashes of Septimius Severus were buried in the temple where rest the bones of the Antonini, has led to the conjecture that the columns formed the colonnade of a round temple on the top of the mausoleum in which temple Hadrian's colossal statue stood, and that the bronze fir-cone found here, which is now in the Vatican garden, ornamented the summit. Round this temple, and upon the level top of the cylindrical tower, may have been arranged the various statues of which Procopius speaks.

The colossal head of Hadrian's statue found here is still to be seen in the Museo Pio Clementino, the bronze gilt peac.o.c.ks in the Giardino della Pigna. The famous Barberini Faun, now at Munich, and the dancing Faun at Florence, were amongst the ornaments of the upper part of the tomb.

Another conjecture as to the shape of the upper part of the building is that it was surmounted by a smaller cylindrical tower, with a roof in the shape of a truncated cone, upon the top of which stood the colossal statue of Hadrian. There is not sufficient evidence to give any degree of certainty to either of these conjectural restorations.

The interior of the building, according to the latest discoveries, consists of a large central rectangular chamber (thirty-six by thirty feet wide and fifty-four feet high), approached by an ascending spiral corridor, leading from a lower chamber which communicated immediately with the princ.i.p.al entrance. The entrance was a high arch in the cylindrical tower immediately opposite the bridge; it is now walled up and the lower chamber into which it leads can only be approached from above.

In the central chamber there are four niches in which formerly stood the urns and tombstones of the ill.u.s.trious persons buried here. A large sarcophagus of porphyry found here was used for the tomb of Pope Innocent II. in the Lateran, and the lid may still be seen in the Baptisterium of St. Peter's, where it is used as a font. The chamber was lighted and ventilated by square pa.s.sages cut through the stone in a slanting direction, and the rain water was carried off by other channels, which conveyed it into drains at the foot of the building. It does not appear to be certainly known whether other chambers may not exist in the interior which have not been yet discovered. Piranesi gives a number of additional chambers besides the two above mentioned, but his representation is probably conjectural.

After the burial of Nerva no more room was left in the Mausoleum of Augustus for the interment of the imperial ashes. Trajan's remains were deposited under his column in the forum bearing his name, but Hadrian gladly seized the opportunity of adding another to the many colossal structures he had already reared. The mausoleum was begun at the same time with the aelian bridge in the year A.D. 135. The bricks of which part of the building consists have stamps of various years of Hadrian's reign, and show that the greater part of the building was erected by him, though Antoninus Pius probably completed it. Hadrian's son aelius, who died before his father, was the first Caesar whose ashes were placed in this tomb.

After him, Hadrian himself was buried here, and then the Emperor Antoninus Pius, and his wife the elder Faustina, three of their sons, Fulvius Antoninus, M. Galerius Aurelius Antoninus, and L. Aurelius Verus, the colleague of M. Aurelius in the empire, and a daughter Aurelia Fadilla.

No record has been preserved of the burial of M. Aurelius, but it seems probable that his ashes were deposited here, as the Mausoleum of Hadrian continued to be the tomb of the Antonines till the time of Severus, who built a third imperial monument, the Septizonium, on the Appian Road.[106]

Four children of M. Aurelius were buried here, who died during their father's life, named Aurelius Antoninus, T. aelius Aurelius, and Domitia Faustina, and also his miserable son and successor the Emperor Commodus.

The inscriptions recording all these burials, were copied by the anonymous writer of Einsiedlen in the ninth century, when they were apparently still legible upon the south wall of the square bas.e.m.e.nt. The inscriptions recording the names Hadrian and M. Aurelius may have been placed upon the upper part of the tomb, like those on the Plautian Tomb and the Tomb of Caecilia Metella, and may therefore either have escaped the notice of the above-mentioned anonymous traveller, or have been stripped off with the marble casing of the exterior.

After the burial of M. Aurelius the tomb was closed until the sack of Rome by Alaric in A.D. 410, when this barbarian's soldiers probably broke it open in search of treasure, and scattered the ashes of the Antonines to the winds. From this time for a hundred years the tomb was turned into a fortress, the possession of which became the object of many struggles in the wars of the Goths under Vitiges A.D. 537 and Totilas who was killed A.D. 552. From the end of the sixth century, when Gregory the Great saw on its summit a vision of St. Michael sheathing his sword in token that the prayers of the Romans for preservation from the plague were heard, the Mausoleum of Hadrian was considered as a consecrated building under the name of S. Angelus inter nubes, usque ad caelos, or inter caelos, until it was seized in A.D. 923 by Alberic, Count of Tusculum and the infamous Marozia, and again became the scene of the fierce struggles of those miserable ages between popes, emperors, and reckless adventurers.[107] The last injuries appear to have been inflicted upon the building in the contest between the French Pope Clemens VII. and the Italian Pope Urban VIII. The exterior was then finally dismantled and stripped. Partial additions and restorations soon began to take place. Boniface IX., in the beginning of the fifteenth century, erected new battlements and fortifications on and around it, and since his time it has remained in the possession of the Papal Government. The strange medley of Papal reception rooms, dungeons, and military magazines which now enc.u.mbers the top was chiefly built by Paul III. The corridor connecting it with the Vatican dates from the time of Alexander Borgia (A.D. 1494), and the bronze statue of St. Michael on the summit, which replaced an older marble statue, from the reign of Benedict XIV.[108]

CHAPTER VII.

THE QUIRINAL HILL--BATHS OF DIOCLETIAN--AGGER OF SERVIUS--CASTRA PRaeTORIA.

[Sidenote: Baths of Diocletian.]

The broad flat s.p.a.ce to the N.E. of the Quirinal Hill, was occupied by the Thermae of Diocletian, now converted into the great Church of S. Maria degli Angeli. This enormous group of buildings was the most extensive of all the gigantic edifices of the empire, and the ground plan is not difficult to trace by the aid of the existing ruins. Some idea of their dimensions will be given by remarking that the grand court enclosed a s.p.a.ce once occupied by the church, monastery, and s.p.a.cious garden of the Monks of S. Bernard, the great church and monastery of the Carthusians, two very large piazzas the large granaries of the Papal Government, part of the grounds of the Villa Montalto Negroni, and some vineyards and houses besides. The north-western side of this grand court is now only marked by the remains of two semicircular tribunes in front of the railway station. The rest of the foundations of this side are hidden under the great cloister of the Carthusian monastery, and in the district beyond.

The princ.i.p.al entrance was on this side. The south-eastern side is now occupied by the buildings of the railway station, at the back of which were discovered the ruins of a large reservoir now destroyed (K), in the shape of a right-angled triangle. The peculiar form of this building seems to have been necessitated by the course of a public road of some importance confining it on the south side, and it has been supposed, not without reason, that this was the princ.i.p.al road leading out of the city at the Porta Viminalis. The interior was filled with pillars like those which still stand in the ancient reservoirs at Baiae and Constantinople.

[Ill.u.s.tration: The Quirinal Hill, as seen from the Palatine.]

On the south-western side of the court there are considerable remains. In the gardens of the monastery of S. Bernardo, part of the cavea of a theatre (A) with a radius of about seventy yards, may be traced, not unlike that in the Thermae of t.i.tus. The seats of this are gone, but parts of the back wall with niches remain. On each side of this are traces of rectangular chambers, and at the corners stand two round buildings, one of which is nearly perfect, and has been converted into the Church of S. Bernardo. The ancient domed roof with its octagonal panelled work is still standing. Part of the other rotunda at the southern corner is also left, and has been built into the end of the Via Strozzi.

[Ill.u.s.tration: THERMae DIOCLETIANae. (PALLADIO.) _The red lines mark the conjectural restorations._]

The north-western side of the court ran parallel to the Via di Venti Settembre from the Church of S. Bernardo. It contained, according to Palladio's plan, two semicircular exedrae (LL) for philosophical conversation or disputation, and some other rooms the purpose of which is not known. The Ulpian libraries are said to have been transferred to these baths from the Forum Trajani. In this s.p.a.cious court stood a great pile of buildings, the centre of which was occupied by a great hall (D), now the church of S. Maria degli Angeli. The pavement of this was raised above the ancient level of the ground by nearly eight feet, when Michael Angelo undertook to convert the ancient building into a church, and thus the bases of the columns remain buried, and new bases of stucco work have been placed round them. This roof must therefore have been in ancient times considerably more lofty than at present. The ancient roof was 120 feet high, and roofed as now, with an intersecting vault in three compartments, supported by the eight colossal ancient granite pillars. These columns of Egyptian granite with their Corinthian and composite capitals form the sole relic of the magnificence of the hall. In the modern church the transept corresponds to the longer axis of the ancient hall, and the nave to the shorter. Vanvitelli, who altered the arrangement of the church in 1749, threw out an apse for the choir on the north-east side, and made the circular laconic.u.m (C) of the old Thermae serve as an entrance porch.

Antiquarians are not agreed as to the purpose of this great central hall.

Scamozzi, in his edition of Palladio, calls it a xystus for athletic exercises, but, following the a.n.a.logy of the Thermae of Caracalla, the baths at Pompeii, and some of the other great thermae, we should rather suppose it to have been the tepidarium. This view is confirmed when we notice that the laconic.u.m or sudarium (C) is on one side, and the natatio (F) for the cold baths on the other, between which the tepidarium was kept at a mean temperature.

The two wings of the central building were occupied by large peristylia, with cold piscinae in the centre of each (EE). Round these peristylia were built various rooms for athletic exercises, called sphaeristeria and gymnasia.

The style of brick building used in these Thermae, recalls that of the Basilica of Constantine, where we see the bricks irregularly and hastily laid; and the whole of the architectural details which have been preserved seem to point to the same period. Positive evidence of the date and the builder is not however wanting. An inscription, which was still to be seen two hundred years ago in the thermae, and which has been partially preserved to us, when compared with three others which were found in the neighbourhood, shows that Maximia.n.u.s gave orders for building these thermae when he was absent in Africa, during his Mauretanian campaigns, and intended them to be dedicated to the honour of his brother Diocletian. The dedication took place after the abdication of Diocletian and Maximia.n.u.s, when their successors Constantius Chlorus and Galerius Maximia.n.u.s had begun their reign, A.D. 305, but before the death of Constantius in 306.

The old chronologers place the date of the commencement of the buildings in 302, which agrees very well with the date of the Mauretanian campaigns of Maximian.

Baronius accounts for the preservation of so large a part of these thermae by the statement that they were considered to be a monument of the Diocletian persecution. There was a tradition, he says, that Diocletian, after dismissing some thousands of his soldiers because they held the Christian faith, compelled them to work as slaves in the erection of his thermae, and ordered them to be martyred when they had finished the building. It has also been said that the bricks are in some cases marked with a cross, but this is not well authenticated.