Cathedral of Saint Michael and Saint Gudula

Stand at the foot of the wide stone steps and look up. Two square towers rise side by side, pale against the Brussels sky. There are no spires on top — just flat crowns, as if the builders stopped to rest and never picked up their tools again. Behind you, traffic hums along the boulevard. In front of you, the stone is quiet. Take a breath here, because what you are looking at took roughly three centuries to finish.

This is the Cathedral of Saint Michael and Saint Gudula, the main Catholic church of Belgium's capital. It sits on a slope between the upper town, where dukes and kings once lived, and the lower town, where merchants traded. That position was no accident. A church on this hill could be seen from the river valley below. For centuries, it marked the city from a distance, long before office blocks grew up around it.

Work on the Gothic building you see today began in the first half of the thirteenth century, under the dukes of Brabant. Brabant was a powerful medieval duchy, and Brussels was one of its leading towns. The builders worked slowly. They started with the choir at the eastern end, then moved westward, bay by bay, generation by generation. The two towers on the main front were only completed in the late fifteenth century. Many of the masons who laid the first stones never saw the last ones.

Here is the first surprise. For most of its long life, this was not a cathedral at all. It was a collegiate church — a large church served by a group of clergy, but without a bishop's throne. It only received cathedral status in 1962, when the archdiocese of Mechelen and Brussels was reorganised. So the title on the door is younger than many of the people who visit. The building, of course, is very much older.

Now, the two names. Saint Michael is the archangel, the warrior of heaven who defeats the dragon. He is also the patron saint of Brussels, and you will see him again on the town hall spire in the Grand Place. Saint Gudula is a local saint from the early Middle Ages, a young noblewoman remembered for her devotion. Her relics were brought to this hill in the eleventh century, and over time her name joined Michael's on the church.

Legend has it that Gudula walked to prayer before dawn, carrying a lantern. A devil, jealous of her faith, blew out the flame again and again. Each time, according to the tale, an angel relit it. This is folklore, not history — but it explains why Gudula is so often shown holding a small lamp, sometimes with a tiny demon close by. Once you know the story, you start to notice that lantern everywhere.

Step inside and let your eyes adjust. The nave is long and tall, lined with heavy round columns. The style is called Brabantine Gothic, a regional form of Gothic that is a little plainer and more solid than the soaring churches of France. Look at the columns themselves. Against them stand large stone figures of the twelve apostles, added in the seventeenth century. They lean forward slightly, as if they are watching the congregation walk past.

Halfway along the nave, you reach something remarkable: the pulpit. It is carved entirely from wood, in the extravagant Baroque style of the late seventeenth century, by the Antwerp sculptor Hendrik Frans Verbruggen. At the base, Adam and Eve are driven out of Paradise. Above them, trees, birds and animals climb towards the canopy. At the very top, the Virgin Mary stands on a serpent. The whole pulpit tells one story, from the fall of humanity to its hope of rescue.

Now turn your attention upward, to the windows. Some of the finest stained glass in the city fills this building, much of it from the sixteenth century. In the transepts — the arms of the cross-shaped plan — the great windows show members of the Habsburg family kneeling in prayer. Among them is Emperor Charles the Fifth, who was born in nearby Ghent and grew up in these lands. The designs are linked to the court painter Bernard van Orley. On a sunny day, red and blue light falls across the floor.

Here is the second surprise, and it is under your feet. In parts of the nave and below the choir, the floor opens to show older stonework. Excavations in the late twentieth century found the remains of the earlier Romanesque church that stood here before the Gothic one. Romanesque is the heavier, round-arched style that came before Gothic in Europe. You can look down at these foundations and see, quite literally, one church built on top of another.

This building also carries a difficult chapter. One chapel is linked to a fourteenth-century story about stolen and desecrated communion bread, a story that was used to accuse and persecute the Jews of Brussels. For centuries the tale was celebrated. Today the church presents it differently, and a plaque acknowledges that the accusations were false and harmful. It is worth pausing here. A great church holds beauty, but it also holds the mistakes of the people who filled it.

The cathedral remains at the centre of national life. Royal weddings and state funerals take place beneath this roof. The funeral of King Baudouin was held here in 1993, and his nephew Philippe, now king, married Mathilde here in 1999. On ordinary days, though, it is calmer. You might hear an organist practising, a tour group whispering, or simply the echo of footsteps on stone. The large modern organ in the nave was installed around the turn of the millennium.

When you leave, stop again on the steps and turn around. Look at the pale stone of the façade. It was cleaned during a long restoration, so it is much lighter than it appeared to Brussels residents a few generations ago. From here, the streets lead down towards the old centre and the Grand Place. As you walk, notice how often the two towers reappear between the buildings behind you — still marking the hill, as they have for more than five hundred years.