The persecution of Diocletian ended in 306, but it was not until 311 that the Catacombs were restored to their natural owners and protectors, the Bishops of Rome. In that year the Pope Melchiades sent, by the hands of some of his deacons, letters from the Emperor Maxentius to the Prefect of the city, that he might recover legal possession of all “the ecclesiastical places” of which the Christians had been plundered; and amongst these places, the cemeteries were the most precious. About this time, if not earlier, other cemeteries also were made, more easily and at less cost, above ground instead of below; and during the next hundred years both places of burial were in use. If we may take the dated inscriptions as a guide in estimating the relative proportions in which they were used, we should say that burial in the Catacombs remained in the greatest favour until the latter half of the century. From the year 364 to the end, the balance is considerably on the other side; only one-third of the burials appear to have been in the subterranean cemeteries, and two-thirds above ground. Then from the year 400 to 410, burial in the Catacombs became more and more rare, until in that year it ceased altogether.

The portions of the Catacombs that were excavated during the fourth century vary considerably in character. In some parts, everything is on an exceptional scale of grandeur; the chambers are not only double, one on either side of the gallery, but even treble and quadruple, and of magnificent proportions. In other parts, on the contrary, there is nothing but a number of miserable galleries, executed with great economy, and destitute of all ornament; evidently they were required to meet the increasing wants of a large Christian population. It is during this same period that we meet with inscriptions recording contracts for the purchase of graves, and many more which, without entering into details, merely declare that the deceased had provided during his lifetime a place of burial for himself alone, or for himself and his wife, and perhaps some other relatives also. These have very rarely been found in the more ancient parts of the Catacombs. Indeed, such purchases would have proved a fruitful source of embarrassment in the days of persecution, when the fossors often used galleries whose walls had been already filled with graves as a convenient place in which to deposit the soil removed from the new galleries they were excavating, and sometimes even buried corpses in the pathways which they had thus filled. But this could not have been done if it had been necessary to reserve particular spots as the private property of persons hereafter to be buried there.

In the earliest of the inscriptions which record the purchase of graves, the fossors appear as the vendors; indeed, towards the end of the fourth century, it would almost seem as though the whole administration of the Catacombs had fallen into their hands. Each fossor now worked either independently, or with a partner if he preferred it; at least, the purchase is generally stated to have been made from one fossor, occasionally from two; and if the names of others of the same class are added, it is only to say that they assisted as witnesses of the contract. Once we even find the family of a fossor selling the graves which their father had excavated. In several of the inscriptions the price is named, as well as the names of the contracting parties; and some authors have attempted to estimate from these examples the ordinary cost of a grave in the Catacombs. Their calculations, however, cannot be accepted, for several reasons. First, the recorded prices are, in every instance, out of all proportion with the labour really expended on the grave; and secondly, they vary immensely, yet not according to any fixed principle. It seems safer, therefore, to conclude, with De Rossi, that the price was in each case proportionate to the means and good-will of the purchaser, that so provision might be made for the gratuitous burial of the poor out of the superabundant payments of the wealthy.

Another and a more important change than any which has yet been mentioned came over the Catacombs during the fourth century. It has been already mentioned that the devotion of the faithful naturally led them to look on the tombs of the martyrs with feelings of the most tender and pious affection; they desired, therefore, to manifest their love by some outward tokens—to exchange the primitive simplicity of their humble graves for something more suitable to their own altered condition. From the first moment, then, that it was possible, even in the very age of Constantine, grand basilicas were built over the tombs of the more celebrated saints, St. Peter, St. Paul, St. Agnes, St. Sebastian, and others. In all these instances, they aimed at enclosing the tomb they desired to honour within the precincts of the church; indeed, this was, of course, the central point of devotion in the new building. But it was impossible to dig the foundations and build the walls of such vast edifices without a great destruction of subterranean graves and galleries throughout the whole neighbourhood. Probably there were always some who regretted this necessity, and who would have preferred to see these venerable monuments of primitive Christianity left in their original form. Certainly at the end of some fifty or sixty years, about the year 370, there sat in the chair of Peter one who seems to have entertained these feelings, and who devoted himself therefore with singular zeal and prudence to the work of their preservation.

Pope Damasus (for it is he of whom we are speaking) sought diligently for all the tombs of historical note that had been hidden in days of persecution and not yet recovered. He had no means, indeed, nor apparently any desire, to crown them with basilicas of royal grandeur such as Constantine had built; but he did what he could, and what he thought necessary, both for the avoidance of scandal and danger among the innumerable pilgrims who now flocked from all parts of the world to visit the tombs of the martyrs, and also to preserve their memory to future generations. First, therefore, he made new staircases and additional shafts to the upper world to admit more light and air; he blocked up certain passages, so as to check indiscriminate rambles in the subterranean labyrinth, and to guide the pilgrims perforce to those particular shrines where they wished to pay their homage. He strengthened the friable tufa walls of some of the galleries which needed support by means of arches of brick and stone work. He enlarged some of the chambers, and ornamented many more; sometimes encasing their walls from top to bottom with marble; sometimes—“not content with Parian marble,” as Prudentius says—even using much solid silver for the ornamentation of very special shrines. Finally, he composed short sets of verses in honour of some of the heroes he desired to honour—verses in which he either relates some interesting circumstance of their history which would otherwise have been lost, or records the repairs or ornaments which had been his own work. These inscriptions have been of the utmost service in fixing the geography of the cemeteries, and so in reconstructing their history. They are all exquisitely engraved on marble, and set up at the spots to which they severally belong; engraved, too, invariably by the same hand, the hand of an accomplished artist, Furius Dionysius Filocalus, who devoted himself to this work out of special love, as it would seem, to the Pontiff whom he so ably served.

The devotion of Pope Damasus to the Catacombs was as intelligent as it was ardent. He longed, as he himself tells us, to be buried in them, in a chamber where many of his martyred predecessors and other saints already lay; but he respected too much the integrity of their tombs, and prepared his place of burial therefore elsewhere. He built a place for the purpose aboveground, in which himself, his mother, and sister, were all buried. It would have been a happy thing for Christian archæology if others had been equally scrupulous; but numerous epitaphs tell us of men and women who had secured for themselves by purchase the right of a grave “behind the saints” (retro sanctos) or “near” (ad) such and such a saint, i.e., near his tomb; and many a subterranean chapel still testifies, by the destruction of its original decorations, to the frequent gratification of this natural desire. It is not improbable that Pope Damasus forbade its indulgence to others, as he certainly denied it to himself. Anyhow, there was a rapid decline in the number of those who were buried in any part of the Catacombs during the latter part of his Pontificate.

Then came the fatal year 410, the year in which Rome was taken by Alaric,—the year in which, as St. Jerome says, “the most beautiful light of the world was put out: the Roman Empire was decapitated, and, to sum up all in one word, in the destruction of one city the whole world perished.” In this year, the use of the Catacombs as Christian cemeteries came to an end, and it was never again resumed. Here and there, at rare intervals, a few exceptions may be found, even down to the middle of the fifth century; but, speaking generally, it may be said that they now ceased to be places of burial, and were only henceforth places of pilgrimage.

In 557, much mischief was done in them by the Goths, attracted, perhaps, by some report of the Parian marble and solid silver of which Prudentius had written with such enthusiasm. The mischief was repaired in part by the generosity of the people, in part by the care of the Popes. Pope Vigilius (A.D. 550) restored some of the monumental inscriptions of Pope Damasus which had been broken. It must be acknowledged that his restorations were not very successful; but this was not through any fault of his. Those were days of continual alarm and violence, and literature and the fine arts do not flourish in such an atmosphere. The artists, therefore, whom Vigilius had at his command were not worthy successors of Filocalus; they were both ignorant and unskilful. Sometimes they do not seem to have known the Latin words they had to reproduce, and, when they knew them, often they could not spell them. They committed many offences against the laws both of prosody and of orthography. Nevertheless, we owe the Pope a debt of gratitude for having done what he could, for he has preserved to us some valuable records which would otherwise have perished.

During the next two hundred years matters did not mend. We read of many ordinances by the Popes designed for the protection of the cemeteries and for the celebration of mass in them. But by and by, when the Lombards attacked Rome in 756, the work of ruin made fresh and rapid strides, and, in fact, was soon completed. These men were Arians, and they broke in and carried off some bodies of the saints to take them home to their own churches in the North of Italy; so that, immediately afterwards, Pope Paul I., finding himself quite unable effectually to protect so many cemeteries situated all round the city and so far from its walls, determined to bring the bodies of the martyrs for safer custody into churches within the city. This work of translation, as it was called, though not continued by either of his immediate successors, was resumed by Pope Paschal I. in 817, and carried on by others, the latest instance on record belonging to the days of Leo IV. (A.D. 848). All these Popes assign as the cause for the translation the state of ruin to which the cemeteries were now reduced, and the horrible profanation to which they were continually exposed, parts of them being even used by farmers of the Campagna for the stabling of their sheep and oxen. From this time the real living history of the Catacombs was at an end. As in the beginning of the fifth century they had ceased to be used as places of burial, so in the first half of the ninth they ceased to be frequented for purposes of devotion. Henceforward there was nothing to keep them in the minds and hearts of men. They were neglected and then forgotten.

A few exceptions must be made to these remarks. To some cemeteries religious congregations of men or women had been attached from a very early date. These houses were established for the singing of the Divine praises day and night, in continuation of the primitive practice, when clergy and laity used to keep watch and sing psalms and hymns at the martyrs’ tombs. As long as this was done, the adjoining cemeteries remained at least partially accessible, and were preserved from utter oblivion. This is why we read of occasional visits to the Catacombs of St. Agnes, St. Cyriaca, St. Sebastian, and one or two others, even during the eleventh and twelfth centuries. Numerous inscriptions, which the making of the modern Campo Santo in Rome has lately brought to light, demonstrate that there was a convent of nuns near San Lorenzo fuori le mura, as early as the fourth century. There had been another at the Basilica of St. Agnes since the days of Constantine; and Pope Sixtus III. established a congregation of men at the Basilica of St. Sebastian on the Via Appia. This last has an interesting connection with our subject; for the cemetery at St. Sebastian’s, which had been the temporary resting-place of the bodies of the Apostles Peter and Paul, was known as the Cemetery ad Catacumbas. How it came to be so called, or what is the meaning of the name, scholars are not agreed; neither would the settlement of the question add much to our knowledge of the Catacombs themselves, any more than if we could discover why another cemetery was called “The Cemetery at The Two Laurels” (ad duas lauros), and another, “The Cemetery at Cucumber Hill” (ad divum cucumeris). An accidental importance, however, attaches to the name of this particular cemetery, because it is now given also to all the other subterranean cemeteries of Rome, and even to the cemeteries of Naples, of Paris and Malta, of Sicily and Egypt, some of which have hardly any characteristics in common with them.