In the first century, the Christians of Rome did not have their own cemeteries and used common burial places. For this reason, Saint. Peter was buried on Vatican Hill accessible to everyone; similarly, saint Paul – in the necropolis on Via Ostiense. Over time, the Christian community decided that it was necessary to create separate burial places for the followers of Jesus.
One of the reasons for this decision was that Christians rejected the crematory burial commonly used by followers of traditional Roman beliefs. The establishment of separate cemeteries for Christians on the surface was also difficult due to the high price of land in the Eternal City.
St. Catacombs Callixtus belong to the largest and oldest in Rome. Established around the middle of the second century and are part of a cemetery complex, covering an area of fifteen hectares, with a network of corridors almost twenty kilometres long, in some places they reach more than twenty meters deep. Sixteen popes and almost half a million people were buried in them. Their name comes from the name of deacon Callisto, who at the beginning of the third century Pope Zephyrinus was appointed to manage the cemetery. Then also the Catacombs of St. Callisto became the official cemetery of the Church of Rome.
The underground cemetery consists of many parts. The most important place of the cemetery is the so-called Pope’s Crypt, called the “little Vatican”, because nine of the Popes from the 3rd century were buried there. On the walls, there are original inscriptions in Greek about five popes. In the fourth century, Pope Damasus transformed this crypt into a place of worship. He ordered to put an altar in it, of which only the ancient marble pedestal has survived. Two light holes were cut in the ceiling and columns supporting architraves were placed, from which lamps and crosses hung in honour of martyrs.
The Milan Edict, issued in 313 jointly by the emperors Constantine the Great and Licinius, gave Christianity a legal status in the Empire and caused a gradual transfer of Christian burials to the surface. The last burials in the catacombs date back to the middle of the fifth century.
During the early Middle Ages Catacombs of St. Callixtus were changed into a place of worship where worshipers of the 3rd century were worshipped. Regular pilgrimages were held to the burial sites of the saints from the fifth to the eighth century. Also, mosaics and inscriptions carved on the walls by pilgrims come from this period. In the 8th and 9th centuries, after the Catacombs were looted by the Lombards, the relics were ordered to be transferred to churches in Rome. Over time, the catacombs became deserted and the memory of them blurred. Overgrowing the entrances and landslides led to the catacombs being blocked. During the late Middle Ages, the underground corridor system was widely recognized, but there were no sources to indicate where the entrances were.
Exploration and scientific research of the catacombs began at the end of the 16th century thanks to Antonio Bosio (1575-1629), nicknamed “Columbus of Rome Underground”. In 1593 he discovered the entrance to the Domitilla Catacombs, and in the following years, he managed to locate about thirty underground corridors. After his death, the result of his work was published. On the one hand, this had an impact on further research in the 17th and 18th centuries, and on the other, the spread of the legend of underground treasures brought another catastrophe wave of looting and irretrievable destruction of the monuments therein. The catacombs of Saint Callixtus were not found until 1854 by Giovanni Battista de Rossi.