The Catacombs of Rome are underground tunnels and chambers excavated as burial places in or near Rome, many of them built by Jews or, later, by Christians. Some Jewish Catacombs may predate the Christian era, but most catacombs date from the 2nd century A. D. or later. They were carved in tufa (soft volcanic ash). Roman law forbade burial within the city; and the Jews and Christians rejected the Roman custom of cremation because of belief in the resurrection of the body, and did not own the land necessary for burials above ground. They were built along Roman roads. They were used for burial and memorial services, but probably not for regular worship. They may have been also used by Christians as refuges during persecution; Pope Sixtus II was captured in one of the Catacombs during the persecution under Valerian in 258 A. D. with four deacons (although it is not clear what he was doing there).
The catacombs contain many examples of early Christian art. After the legalization of Christianity by Constantine in 313 A. D. the practice of burying Christian dead in catacombs declined, and it ceased altogether after the sack of Rome by the Visigoths in 410 A. D.
The Good Shepherd with the Kid
by Matthew Arnold
"He saves the sheep, the goats he doth not save."
So rang Tertullian's sentence, on the side
Of that unpitying Phrygian Sect which cried:
"Him can no fount of fresh forgiveness lave,
Who sins, once washed by the baptismal wave."
So spake the fierce Tertullian. But she sighed,
The infant Church! of love she felt the tide
Stream on her from her Lord's yet recent grave.
And then she smiled; and in the Catacombs,
With eye suffused but heart inspired true,
On those walls subterranean, where she hid
Her head in ignominy, death, and tombs,
She her good Shepherd's hasty image drew
And on his shoulders, not a lamb, a kid.