Lasers Reveal First Icons of Sts. Peter and Paul

Twenty-first century laser technology has opened a window into the early days of the Catholic Church, guiding researchers through the dank catacombs beneath Rome to a startling find: the first known icons of the Apostles Peter and Paul.

Vatican officials on Tuesday unveiled the paintings, located in an underground burial chamber under an eight-story modern office building on a busy street in a working-class neighborhood of Rome.

The images, which date from the second half of the 4th century, were uncovered using a new laser technique that allowed restorers to burn off centuries of thick white calcium carbonate deposits without damaging the brilliant dark colors of the original paintings underneath.

The technique could revolutionize the way restoration work is carried out in the miles (kilometers) of catacombs that burrow under the Eternal City where early Christians buried their dead.

The icons, which also include the first known images of the apostles John and Andrew, were discovered on the ceiling of a tomb of an aristocratic Roman woman at the Santa Tecla catacomb, near where the remains of the apostle Paul are said to be buried.

Rome has dozens of such catacombs and they are a major tourist attraction, giving visitors a peek into the traditions of the early Church when Christians were often persecuted for their beliefs. Early Christians dug the catacombs outside Rome's walls as underground cemeteries, since burial was forbidden inside the city walls and pagan Romans were usually cremated.

The art that decorated Rome's catacombs was often simplistic and symbolic in nature. The Santa Tecla catacombs, however, represent some of the earliest evidence of devotion to the apostles in early Christianity, Vatican officials said in announcing the discovery.

"The Christian catacombs, while giving us value with a religious and cultural patrimony, represent an eloquent and significant testimony of Christianity at its origin," said Monsignor Giovanni Carru, the No. 2 in the Vatican's Pontifical Commission of Sacred Archaeology, which maintains the catacombs.

Last June, the Vatican announced the discovery of the icon of Paul at Santa Tecla, with the announcement timed to coincide with the end of the Vatican's Pauline year. At the time, Pope Benedict XVI also announced that tests on bone fragments long attributed to Paul "seemed to confirm" that they did indeed belong to the Roman Catholic saint.

On Tuesday, Vatican archaeologists announced that the image of Paul discovered last year was not found in isolation, but was rather part of a square ceiling painting that also included icons of three other apostles - Peter, John and Andrew - surrounding an image of Christ as the Good Shepherd.

"They are the first icons. These are absolutely the first representations of the apostles," said Fabrizio Bisconti, the superintendent of archaeology for the catacombs.

Bisconti spoke from inside the intimate burial chamber, whose entrance is crowned by a red-backed painting of the 12 apostles. Once inside, visitors see the loculi, or burial chambers, on three sides. But the gem is in the ceiling, with each of the apostles painted inside gold-rimmed circles against a red-ochre backdrop. The ceiling is also decorated with geometric designs, and the cornices feature images of naked youths.

Chief restorer Barbara Mazzei noted that there were earlier known images of Peter and Paul, but they were depicted as if in narratives. The images on display in the catacomb - with their faces in isolation, encircled with gold and affixed to the four corners of the ceiling painting - are devotional in nature and as such represent the first known icons.

"The fact of isolating them in a corner tells us it's a form of devotion," she said. "In this case, Sts. Peter and Paul, and John and Andrew are the most antique testimonies we have."

In addition, the images of Andrew and John show much younger faces than what are normally depicted in the Byzantine-inspired imagery most often associated with the apostles, she said.

The Vatican's Sacred Archaeology office oversaw and paid for the two-year, euro60,000 restoration effort, which for the first time used lasers to restore frescoes in catacombs. The damp air of underground catacombs makes preservation of paintings particularly difficult and restoration problematic.

In this case, the small burial chamber at the end of the catacomb was completely encased in centimeters (inches) of white calcium carbonate. Restoring the paintings underneath using previous techniques would have meant scraping away the calcium buildup by hand. That technique, though would have left a filmy calcium layer on top so as to not damage the paintings underneath.

Using the laser, restorers were able to sear off all the calcium that had been bound onto the painting because the laser beam was concentrated on a chromatic selection: the white of the calcium carbonate deposits. The laser's heat stopped when it reached a different color. That enabled researchers to easily chip off the seared white calcium carbonate, which then revealed the brilliant ochre, black, green and yellow underneath unscathed, she said.

Similar technology has been used for over a decade on statues, particularly metallic ones damaged by years of outdoor pollution, she said. The Santa Tecla restoration, however, marked the first time the lasers had been adapted for use in the dank interiors of catacombs.

The protocol used, she said, would now be used as a model for similar underground restorations where the damage was similar to that found at Santa Tecla, which she said was the most common type of damage found in Rome's catacombs.

Many of Rome's more well-known catacombs are open regularly to the public, such as the Santa Priscilla and San Sebastiano catacombs. The Santa Tecla catacombs will be open to the public only on request to limited groups to preserve the paintings, she said.