
We made our way along the Moselle River toward Germany’s oldest city, passing vineyard covered mountains capped by the ruins of hilltop castles overlooking small villages that hugged the riverbank. Our destination was Trier, on the far western edge of Germany bordering Luxembourg. Known as “Rome of the North,” Trier was founded by the Romans in 15 B.C. Located on the edge of the Roman frontier, it grew to be an important city. When the Roman Empire started to crumble in the fifth century, the Romans withdrew from Trier. The city, conquered by invading barbarian tribes, went into decline before it was revived four hundred years later in the Middle Ages. Today, Trier has the largest collection of Roman ruins outside of Rome.

Trier is not at all close to Rome, and so you might wonder why the Romans chose to build a city so far north?

Part of the reason is that the Moselle River flows from the Rhine River southwest past Trier toward today’s France, so it was a strategic location to control commerce coming down the river. Judging by the river traffic, it was clear that commerce is still important for the city.

High plateaus run along each side of the river where Romans built fortifications to defend against invading tribes. Several Roman highways led through the city making it an important commercial and military center. A Roman bridge that dates from the second century, which was originally wood and later rebuilt in stone, is the oldest bridge in Germany. It still serves as a main crossing into Trier.

On the outskirts, Trier looks like any modern city. Then, as we approached downtown, the remnants of a massive Roman ruin, The Imperial Baths, came into view. It is one of several enormous buildings clustered in the center of what was once a vast Roman settlement.

At the entrance of the city is the Porta Nigra, or “Black Gate,” so called because the stone it’s built of has naturally darkened over time. It was one of four city gates that were integrated into a four-mile wall surrounding Trier. The city served as the headquarters of the Western Roman Empire.

When the Romans built the gate, instead of concrete, they used iron bars to hold the stones together. During the Middle Ages, townspeople scavenged the iron bars, along with the stones, to use for their buildings. Today, the gate is only partially intact, so while the huge Porta Nigra is impressive today, it was even more imposing in Roman times.

In the Middle Ages, the city walls and three of the gates were removed because they no longer served a purpose, but the Porta Nigra was left intact. That’s because a reclusive Greek monk had taken up residence in the gate. Later, after the monk died and was beatified, part of the Porta Nigra became a church and monastery in his honor. Then, in the nineteenth century, when Napoleon occupied Trier (along with much of Germany) he dissolved the church and restored the Roman features of what remained of the gate. Today, the Porta Nigra is the city’s most famous landmark.