Potidaea

Listen first. On the bridge over the canal, a light wind moves between two seas. The water below is green, then blue, then grey again as a cloud passes. A fishing boat slides through the cut with its engine low. On one side lies the Gulf of Thessaloniki. On the other lies the Gulf of Kassandra. You are standing on a narrow neck of land, and that narrowness is the whole story of this place.

This is Potidaea. Today the village here is called Nea Poteidaia, and it sits at the entrance to the Kassandra peninsula, the westernmost of the three fingers of Chalkidiki. Look at a map and you see why people wanted it. Whoever held this isthmus controlled the only land route onto the peninsula. They also watched the sea traffic in two gulfs at once. A small town in a large position.

The ancient city was founded by colonists from Corinth, the powerful trading city near the Peloponnese, in southern Greece. Historians generally place the founding around 600 BC. Corinth sent settlers across the Greek world to build trading posts, and this was one of its northern outposts. Unusually, the colony kept close ties with its mother city for a long time. Corinth even sent officials here each year. Remember that detail. It matters later.

The name itself points to the sea. Potidaea is linked to Poseidon, the Greek god of the sea, of horses, and of earthquakes. Coins struck by the ancient city show Poseidon riding a horse, holding his trident. For a town surrounded by water and shaken now and then by the ground beneath it, that choice of protector makes sense. Here is the first surprise. Poseidon may have defended this town in a way that ancient writers took very seriously.

In 479 BC, after the Persian invasion of Greece, a Persian commander named Artabazus besieged Potidaea. The Greek historian Herodotus tells what happened next. The Persians tried to cross along the shore while the sea had pulled far back. Then the water returned in a great flood and drowned many of them. The people of Potidaea said Poseidon had punished the Persians. Many modern scholars read this account as one of the earliest written descriptions of a tsunami.

Fifty years later, Potidaea found itself caught between two great powers. By then it belonged to the Delian League, an alliance led by Athens. But its old loyalty to Corinth had not disappeared. Athens grew suspicious and made harsh demands. In 432 BC, Potidaea revolted. Athens answered with a long siege. The historian Thucydides lists this crisis among the causes of the Peloponnesian War, the long conflict between Athens and Sparta that reshaped the Greek world.

Now the second surprise. Among the Athenian soldiers outside these walls was a stonemason's son who would become the most famous philosopher in history. Socrates served here as a heavy infantryman. In Plato's dialogue called the Symposium, the young Athenian Alcibiades describes him at Potidaea. Socrates endured the bitter winter barefoot, Alcibiades says, and saved his life in battle. The siege lasted more than two years and ended when the starving town surrendered.

The town survived and changed hands again. In 356 BC, Philip the Second of Macedon, the father of Alexander the Great, captured Potidaea. Some decades later, a Macedonian ruler named Cassander built a new city on this site and named it Cassandreia, after himself. The new city grew large and important in the Hellenistic period, the era after Alexander. The peninsula in front of you still carries his name today. Kassandra comes from Cassander.

Cassandreia lasted for centuries, through Roman rule and into the late Roman world. But the isthmus that made it strong also made it a target. In the sixth century, raiders from the north crossed into the region, and the city was badly damaged. After that, the large ancient city faded. Smaller settlements came and went. What remained was the land, the two seas, and pieces of stone half-buried in the soil.

Look along the edges of the canal. In places you can see fragments of the old fortification walls, built from large cut blocks. They are not dramatic ruins with columns and temples. They are quieter than that. Lines of masonry, the base of a wall, stones fitted together without much decoration. These blocks once stood between the town and every army that came up this narrow strip of land. Some of those armies are named in the oldest history books of Europe.

The canal itself is modern. It was dug in the twentieth century to let boats pass between the two gulfs without sailing around the whole peninsula. In a way, it repeats the logic of the ancient city. Control the narrow point, and you control the movement. Today the canal serves fishing boats and pleasure craft. In summer the bridge fills with cars heading south to the beaches. Few drivers know they are crossing the line of ancient walls.

The modern village has its own history of arrival. Like many towns in this part of northern Greece, it was settled in the early twentieth century by Greek refugees from Asia Minor, in present-day Turkey. They brought their own churches, recipes, and memories. So the people here today are also newcomers to an old site, like the Corinthians long ago. Walk the waterfront and you will find tavernas, fish drying in the sun, and families out in the evening.

So take a moment before you leave. Stand where you can see both gulfs. Feel how narrow this ground really is. Persian soldiers drowned on this shore. Socrates spent a hard winter outside these walls. A Macedonian king put his name on the land. And now a fishing boat moves slowly through the cut below you. As you walk back, watch the low stones near the water. They are easy to miss, and they have been here for a very long time.