Archaeologists working in Rome have unearthed what is believed to be the first iconical representations of Saints Peter, Paul, James and John. The icon was discovered in the catacombs beneath an office building on a busy thoroughfare in Rome. Archaeologists were able to use a laser technique which allows them to burn off white calcium carbonate deposits without damaging the paintings underneath. The images date from the second half of the fourth century and depict Christ as the Good Shepherd in the center of the painting surrounded by the four apostles. The Santa Tecla catacombs are part of a system of of burial grounds which the early Christians used. They were unable to bury their dead within the city walls so they dug the catacombs outside the city walls. The catacombs still have much to tell us about the early history of Christianity.