Santa Pudenziana

Start at the street. Via Urbana is narrow here, lined with shuttered windows and parked scooters, and the traffic noise drops away quickly. Then you notice something odd. The church does not rise up from the pavement. It sits below you. To reach the door, you walk down steps into a sunken courtyard, a few metres under the level of modern Rome. That small descent is your first clue to what this place really is.

This is Santa Pudenziana, one of the oldest places of Christian worship in the city. Rome has risen around it over the centuries. Rubble, rebuilding and new streets slowly lifted the ground level, while the church stayed where it began. When you go down those steps, you return to an older surface of the city. The street that Romans walked many centuries ago is closer to this doorway than to the road behind you.

The building did not start as a church. Archaeologists have found that it grew inside an ancient Roman structure, a bath hall from around the second century. Brick walls from that earlier building still survive inside the fabric of the church. Early Christians in Rome often adapted existing buildings rather than building from nothing. So the shape of the church follows the shape of a Roman room. A place for washing and meeting became a place for prayer.

Now for the story the church tells about itself. Tradition says this was the home of a Roman senator named Pudens. According to the legend, he welcomed Saint Peter as a guest, and the apostle stayed here while he preached in Rome. Pudens is said to have had two daughters, Pudentiana and Praxedes, who cared for persecuted Christians. These stories are much loved, but they are tradition rather than proven history. Historians still debate whether Pudentiana herself ever existed.

The other daughter has a church too. Santa Prassede stands only a short walk from here, close to the basilica of Santa Maria Maggiore. Locals sometimes visit the two sister churches together. It is a neat pairing: two old buildings, two legendary sisters, a few streets apart in the same neighbourhood. If you have time today, the walk between them takes you through some of the quieter lanes of the Esquiline Hill.

Before you go inside, look up at the bell tower. It is medieval, built of warm, reddish brick, with rows of small arched openings stacked one above another. This style of slim brick campanile, which simply means bell tower, appears across Rome. Look closely at the walls and you may spot small inset decorations breaking up the brick. The front of the church, by contrast, is much younger. It dates from a nineteenth century restoration, which is why it looks cleaner and more orderly.

Around the main doorway, look for the carved stone frieze. It shows a band of decoration and small round panels with figures. Many visitors walk straight past it on their way in. But it is a reminder that this church has been patched together over many periods. Ancient walls, medieval brick, later carving, a modern facade. Each generation added something and left the older parts in place.

Now step inside, and let your eyes travel to the far end of the church. Above the altar, in the curved apse, is the reason most people come here. It is a mosaic made around the end of the fourth century or the start of the fifth. That makes it one of the oldest surviving Christian mosaics in Rome. Think about that for a moment. This image was set into the wall while the Western Roman Empire still existed.

At the centre sits Christ on a jewelled throne. He looks less like a distant king and more like a Roman teacher, dressed in gold. He holds an open book. The Latin words on it call him the protector of the church of Pudentiana. Around him sit the apostles, dressed in togas, the formal clothing of Roman citizens. They look like senators gathered in council. Early Christian artists used the visual language of Rome itself to show their new faith.

Behind the figures, look for the city. A row of buildings, roofs and colonnades stretches across the background. Many scholars read it as a heavenly Jerusalem, though some see the real Jerusalem of the time. Above them rises a large jewelled cross on a hill. In the sky around it float four winged creatures: a man, a lion, an ox and an eagle. These are traditional symbols of the four Gospel writers. Two women stand behind the apostles holding wreaths.

Here is the detail most visitors miss. The mosaic is not complete. During a rebuilding of the church in the late sixteenth century, the apse was altered, and the outer edges of the mosaic were cut away. Some apostles were lost entirely. Look at the ends of the row and you can see where the figures stop abruptly. Parts of the surface were also restored and repainted over time. What survives is still remarkable, but it is a fragment.

That same rebuilding gave the church its most richly decorated side chapel. It was created for a powerful Roman family, the Caetani, and it is lined with polished coloured marble in deep reds, greens and creams. Its glossy surfaces feel very different from the softer, older mosaic. Today the church also serves the city's Filipino Catholic community. On Sundays you may hear Mass in Tagalog, and the courtyard fills with families talking after the service.

Before you leave, stand for a moment near the back and look toward the apse once more. Notice how the gold catches whatever light enters the church, changing as clouds pass over the city. Then climb the steps back up to Via Urbana. As you rise, you move forward through Rome's long history, from an ancient floor to a modern street. The scooters and voices return. The old room stays below, quietly keeping its fragment of gold.