The Burning of S. Paul's, July 15, 1823. (From an old print.)

The name of Pope Siricius, who was then governing the church, can still be seen engraved on one of the columns, formerly in the left aisle, now in the north vestibule:—

SIRICIVS EPISCOPVS Α

Ω TOTA MENTE DEVOTVS.

Another rare monument of historical value, in spite of its humble origin, came to light at the beginning of the last century, and was published by Bianchini and Muratori, who failed, however, to explain its meaning. It is a brass label once tied to a dog's collar, with the inscription "[I belong] to the basilica of Paul the apostle, rebuilt by our three sovereigns [Valentinianus, Theodosius, and Arcadius]. I am in charge of Felicissimus the shepherd." Such inscriptions were engraved on the collars of dogs, and slaves, so that in case they ran away from their masters, their legal ownership would be known at once by the police, or whoever chanced to catch them.

In course of time the basilica became the centre of a considerable group of buildings, especially of monasteries and convents. There were also chapels, baths, fountains, hostelries, porticoes, cemeteries, orchards, farmhouses, stables, and mills. This small suburban city was exposed to a constant danger of pillage, on account of its location on the high-road from the coast. In 846 it was ransacked by the Saracens, before the Romans could come to the rescue. For these considerations, Pope John VIII. (872-882) determined to put the church of S. Paul and its surroundings under shelter, and to raise a fort that could also command the approach to Rome from this most dangerous side.

The construction of Johannipolis, by which the history of the classical and early mediæval fortifications of Rome is brought to a close, is described by one document only: an inscription above the gate of the castle, which was copied first by Cola di Rienzo, and later by Pietro Sabino, professor of rhetoric in the Roman archigymnasium (Sapienza), towards the end of the fifteenth century. A few fragments of this remarkable document are still preserved in the cloister of the monastery. It states that Pope John VIII. raised a wall for the defence of the basilica of S. Paul's and the surrounding churches, convents, and hospices, in imitation of that built by Leo IV. for the protection of the Vatican suburb. The determination to fortify the sacred buildings at the second milestone of the Via Ostiensis was taken, as I have just said, in consequence of the inroads of the Saracens, which, under the pontificate of John, had become so frequent. The atrocities which marked their second landing on the Roman coast were so appalling that the whole of Europe was shaken with terror. Having failed in his attempt to secure help from Charles the Bald, John placed himself at the head of such scanty forces as he could gather from land and sea, under the pressure of events. Ships from several harbors in the Mediterranean met in the roads of Ostia; and on hearing that the hostile fleet had sailed from the bay of Naples, the Pope set sail at once. The gallant little squadron confronted the infidels under the cliffs of Cape Circeo, and inflicted upon them such a bloody defeat that the danger was averted, at least for a time. The church galleys came back to the mouth of the Tiber, laden with a considerable booty.

It seems that the advance fort of Johannipolis was finished and consecrated by Pope John soon after the naval battle of Cape Circeo (a. d. 877), because the inscription above referred to speaks of him as a triumphant leader,—SEDIS APOSTOLICÆ PAPA JOHANNES OVANS.

The location of this fortified outpost could not have been more judiciously selected. It commanded the roads from Ostia, Laurentum, and Ardea, those, namely, from which the pirates could most easily approach the city. It commanded also the water-way by the Tiber, and the towpaths on each of its banks. It is a great pity that no stone of this historical wall should be left standing. It saved the city from further invasions of the African pirates, as the agger of Servius Tullius had saved it, centuries before, from the attacks of the Carthaginians. I have examined the ground between S. Paul's, the Fosso di Grotta Perfetta, the Vigna de Merode, at the back of the apse, and the banks of the river, without finding a trace of the fortification. I believe, however, that the wall which encloses the garden of the monastery on the south side runs on the same line with John's defences, and rests on their foundations. We must not wonder at the disappearance of Johannipolis, when we have proofs that even the quadri-portico, by which the basilica was entered from the riverside, has been allowed to disappear through the negligence and slovenliness of the monks. Pope Leo I. erected in the centre of the quadri-portico a fountain crowned by a Bacchic Kantharos, and wrote on its epistyle a brilliant epigram, inviting the faithful to purify themselves bodily and spiritually, before presenting themselves to the apostle within. When Cola di Rienzo visited the spot, towards the middle of the fourteenth century, the monument was still in good condition. He calls it "the vase of waters (cantharus aquarum), before the main entrance (of the church) of the blessed Paul." One century later the whole structure had become a heap of ruins. Fra Giocondo da Verona looked in vain for the inscription of Leo I.; he could only find a fragment "lying among the nettles and thorns" (inter orticas et spineta). The same indifference was shown towards the edifices by which the basilica was surrounded. They fell, or were overthrown, one by one.