Her martyrdom took place in the course of the persecution of the Emperor Valerian, circa A.D. 253–7. Portions of the catacomb which bears her name are of a yet older date than S. Agnes. Among other signs of great antiquity are the Greek inscriptions on various loculi. The cemetery, which has been explored with some care, consists of three stories, of different dates. It was, however, after the burying of the young martyr that the catacomb was developed and assumed considerable proportions, as many of the Christian congregation of Rome were desirous of depositing their loved dead in the immediate neighbourhood of the tomb of Agnes. The Emperor Constantine in the fourth century built the basilica known as S. Agnes over the tomb. There is an inscription on a small marble tablet at Naples, originally brought from Rome, which Armellini considers was originally on the loculus containing the body of the saint. The inscription is as follows:
Agne · Sanc
Tissima
The basilica has been several times restored, but preserves with fair accuracy the original disposition of the Church of Constantine.
When it was first built in the fourth century, as we find in other similar instances, considerable destruction and havoc were wrought in the galleries of the catacomb. The fourth-century builders often mercilessly cut away and destroyed galleries, cubicula, loculi, when they arranged for the foundations and lower stories of the church large or small which arose over the tomb of the special saint and martyr. We would instance as conspicuous examples of this strange disregard of the older burying-places, the Basilicas of S. Domitilla, of S. Laurence, of S. Sylvester; the last-named is built over the Cemetery of S. Priscilla.
The body of S. Agnes was never translated from its original home. In the year 1605, in the pontificate of Paul V, her remains, together with those of her foster-sister the martyr S. Emerentiana, were placed in a silver sarcophagus or urn. This was seen in the year 1901–2, when some work beneath the altar was being carried out.
(3) The Cœmeterium majus in the immediate neighbourhood of the Catacomb of S. Agnes. De Rossi names it the “Ostrian” Cemetery, and connects it with the memories of S. Peter, as being the place where the apostle used to baptize. Marucchi, however, in the light of recent discoveries in the Catacomb of Priscilla on the adjacent Via Salaria, unhesitatingly believes that the site of S. Peter’s work and preaching must be sought for in the last-named cemetery. A brief résumé of Marucchi’s arguments, which are most weighty, will be given when the Cemetery of Priscilla is described.
The glory of this cemetery (Cœmeterium majus), as the memory of S. Peter seems really to belong to the Catacomb of S. Priscilla, is that here was the original tomb of S. Emerentiana, who for her devotion to her foster-sister Agnes suffered martyrdom very shortly after the death of Agnes. The site of the tomb has been ascertained, but the remains of Emerentiana now rest in the silver urn which contains the body of S. Agnes in her basilica beneath the altar.
The appellation “Cœmeterium majus” dates certainly from the fifth century. One of the more striking features of this catacomb is a little basilica not of later construction but belonging to the original work. It is simply excavated in the tufa stone, and is divided into two parts by the passage running through the cemetery. It is a perfect subterranean church, containing separate divisions for men and women. The presbytery and the position of the altar are clearly defined; the very chair for the bishop or presiding presbyter is in its place, as is the pillar on which the sacred oil burned in front of some hallowed sanctuary. We wonder what was the special purpose for which this little church, in the middle of the cemetery, was designed?
The Itineraries mention that various martyrs, whose life-stories are generally unknown to us, were buried here.