Santa Croce in Gerusalemme

Listen for a moment before you go inside. The traffic of the city is softer here. Pine needles lie on the paving, and the wide open square in front of the church feels almost suburban. The air carries the faint smell of cut grass from the old monastery gardens behind the walls. This is the eastern edge of historic Rome, and the church in front of you has stood near this spot for roughly seventeen centuries.

This is the Basilica of Santa Croce in Gerusalemme. The name means Holy Cross in Jerusalem. That sounds strange for a church in Rome, and the name is a clue. This church was built to hold objects that, by tradition, came from Jerusalem itself. For centuries it has been one of the Seven Pilgrim Churches of Rome. Pilgrims walked a long circuit between these seven churches, often in a single day, and this one was a key stop.

The story begins with a woman, not a pope. Her name was Helena, and she was the mother of Constantine, the first Roman emperor to embrace Christianity. In the early fourth century, Helena travelled to the Holy Land. According to tradition, she returned with relics connected to the crucifixion of Jesus. She lived here, in a large imperial residence known as the Sessorian Palace. Part of that palace was turned into a chapel to keep her relics safe.

So, the first surprise is under your feet and inside the walls. This basilica did not begin as a church at all. It began as a hall in a Roman palace. Builders later adapted the old imperial structure, and parts of that ancient brickwork survive inside the present building. When you look at the church, you are looking at layers... Roman palace, medieval basilica, and an eighteenth-century face placed over the top.

Now look at that face — the facade. It is Baroque, the theatrical style of the seventeenth and eighteenth centuries, full of curves and movement. It was added in the mid-eighteenth century, during the time of Pope Benedict the Fourteenth. Notice how the front bows outward in the centre, and how statues line the top against the sky. The curve gives the entrance a sense of welcome, as if the building leans gently toward you.

Then look up and to the side. The brick bell tower is much older. It dates from the twelfth century, the Romanesque period, when Roman builders used simple brick and rows of small arched windows. Look for small coloured discs set into the brick. They are a typical decoration of medieval Roman towers. The contrast is striking. The elegant Baroque front and the plain medieval tower stand side by side, six centuries apart.

Step inside. The nave is long and calm, with granite columns that once belonged to the older basilica. The floor is worth a slow look. Parts of it are Cosmatesque, a medieval Roman craft named after a family of stoneworkers. They cut ancient marble into small pieces of red porphyry, green serpentine and white marble. Then they arranged the pieces into circles, stars and interlocking patterns. Much of that stone was recycled from ancient Roman ruins.

Walk toward the apse, the curved space behind the altar. The large fresco up there dates from the late fifteenth century and is often attributed to the painter Antoniazzo Romano. It tells the Legend of the True Cross. This medieval story follows the wood of the cross across centuries — and it includes Helena's search in Jerusalem. Follow the scenes like a comic strip across the curve. You will see Helena searching, and the cross being raised.

Below the main level is one of the oldest and most atmospheric spaces in the basilica, the Chapel of Saint Helena. Here is the second surprise. Tradition says that Helena brought soil from Calvary, the hill of the crucifixion in Jerusalem. It was spread beneath this chapel floor. That is a pious tradition, not something historians can confirm, but it explains the church's name. In a symbolic sense, this corner of Rome became a piece of Jerusalem.

Look up at the vault of this chapel. A rich mosaic covers it, with Christ at the centre and saints and evangelists around him. The mosaic was renewed during the Renaissance, and art historians still debate which artist designed it. The statue of Helena here also has a hidden history. It is believed to be an ancient Roman statue of a pagan goddess. Later sculptors adapted it, giving it a cross and a new identity.

The relics themselves are kept in a separate chapel, built in the twentieth century and reached by a ramp. The atmosphere changes here. It is quieter and more solemn, and visitors often lower their voices. Inside the reliquaries are objects that tradition links to the Passion. They include fragments of wood said to come from the cross, a nail, and thorns. There is also a worn wooden board called the Titulus Crucis.

The Titulus is said to be part of the sign that hung above Jesus on the cross, with words in Hebrew, Greek and Latin. Its age is a real debate. Some scholars have studied the lettering, and scientific dating has suggested a medieval origin. For the faithful, the meaning goes beyond any laboratory result. For others, the objects tell a story about how medieval Europe valued relics. Either way, it is worth looking closely at the faded letters.

When you leave, take a few minutes to walk around the outside. Right beside the basilica rise the Aurelian Walls, the great brick defences of ancient Rome. Embedded in them are the curved arches of a small Roman amphitheatre, once part of the same imperial palace. Behind the church, monks have long tended a garden. Stand still once more in the square. The pines are moving, and pilgrims and neighbours cross the stones. Here, an empress's palace slowly became a place of prayer.