In 2002, a burst pipe caused a sinkhole to form in the basement of the Istituto Sacra Famiglia, a convent and school located along Rome’s Via Casilina. The sisters were no doubt surprised when the sinkhole revealed not only faulty plumbing in need of repair, but also chambers in which several hundred burials were discovered. These burials, which are believed to date to the end of the second century C.E. or the beginning of the third, were of individuals whose bodies had been carefully but hastily wrapped and deposited at the same time, indicating some sort of mass fatality event. Over the next several years of investigations carried out by the Pontificia Commissione di Archeologia Sacra (Pontifical Commission for Sacred Archaeology), almost 345 individuals were examined and analyzed from an estimated total of more than 1,300.
Such a discovery is in and of itself remarkable and tantalizingly mysterious: What catastrophic event led to the death of more than 1,300 people—mostly young adults, including women—in such a short period of time? But perhaps just as puzzling was another question: What were these evidently non-Christian burials doing in the middle of one of Rome’s most important Christian catacombs?1 These chambers underneath the convent’s ruined basement were indeed firmly ensconced in the catacombs of Saints Peter and Marcellinus, a complex comprising approximately 2.8 miles of galleries on three levels, in which 20,000–25,000 early Christians are buried.
Knowledge of the catacomb itself has always existed, even after it fell out of use as an active burial site (along with most of Rome’s other catacombs) around the beginning of the fifth century. However, such places were then venerated and visited by early pilgrims, as the catacombs were believed to be the resting places of many of Christianity’s early saints and martyrs. According to tradition, Saints Peter and Marcellinus were martyred during the reign of Diocletian and were subsequently interred in their eponymous catacomb at the beginning of the fourth century, by which point the catacombs are believed to have already been in use by the Christian community for several decades. More recently, the catacombs were explored and mapped by the famous archaeologist Giovanni Battistade Rossi at the end of the 19th century, and portions of the catacombs were used as an air-raid shelter by local people during World War II. The convent’s foundations likely hindered exploration of the area directly underneath it, and it would take a broken water line 18 centuries later for the mass burial that pre-dates the catacombs themselves to be discovered in their midst.
The answer to the mystery of how and why these burials came to be here is likely found in the history of the property itself. Prior to the Constantinian age, this area was the location of the barracks of the equites singulares Augusti, a private corps of mounted Imperial bodyguards. The skeletal remains do not display any of the obvious bone trauma consistent with a massacre. The most likely explanation for such a large number of simultaneous fatalities is an epidemic sweeping through the city at the end of the second/beginning of the third century.2 Given the close quarters of the soldiers and their families, such an event would have been particularly devastating in the barracks.
Christians were given the use of the ground underneath the equites’ garrison around the mid-third century by the emperor Gallieneus, a conciliatory gesture from the emperor in order to placate a community that had been savagely persecuted under the reign of his father, Emperor Valerian. When the Christians began to construct the catacombs, the chambers containing the earlier burials were simply incorporated into the growing complex. Several decades later, following the end of the civil war between Constantine and Maxentius, the equites singulares Augusti were disbanded by an irate Emperor Constantine following his victory over Maxentius at the Battle of the Milvian Bridge in 312 C.E.; the unfortunate equites had backed the wrong emperor. The property was then given by Constantine to his mother, Helena. It is here that she constructed her own final resting place. To access the catacombs today, one walks by the ruins of what was once her magnificent mausoleum.
Today, the savvy visitor to Rome can access this extraordinary site. A sinkhole in the basement of a convent opened a subterranean door to an archaeological mystery, the investigation of which led to a concerted effort by the Pontifical Commission to undertake extensive excavations and repairs of the catacombs. After several years of painstaking and beautifully executed restoration work, the catacombs of Saints Peter and Marcellinus boast some of the most skillfully rendered and restored frescoes of any of the city’s subterranean burial sites. Particularly noteworthy are its many fine depictions of the concept of refrigerium, a custom borrowed by the Christians from the Greek and Roman tradition of holding funerary banquets in honor of the deceased. In the Christian ethos of this era, this custom came to be closely tied to the sacrament of the Eucharist, and banqueting scenes from the context of the Roman catacombs are among the earliest known images in the canon of Christian art. What began as a plumbing headache for the dismayed sisters of the Istituto Sacra Famiglia turned out to be a serendipitous catalyst for the opening of one of Rome’s most enigmatic sites.3