Temple of Castor and Pollux

Listen for a moment. The gravel crunches under your shoes. Swifts cut sharp circles overhead. Around you, the Roman Forum lies open to the sky, a field of broken stone and pale dust. Rising above it all are three white columns, standing side by side, holding up a narrow strip of carved marble. Look up at them now. They are among the most photographed ruins in Rome, and yet most people walk past without knowing whose house this once was.

This was the Temple of Castor and Pollux, the divine twins. In Greek myth they were the Dioscuri, sons of Zeus and the Spartan queen Leda. One brother was mortal and one was immortal. When the mortal Castor died, Pollux refused to live without him. So the gods allowed the pair to share their fate, and they became the constellation Gemini. The Romans took these Greek twins and made them protectors of their own city.

The story of why the temple stands here begins with a battle. In the early years of the Roman Republic, Rome fought its Latin neighbours at a place called Lake Regillus. Ancient writers place this battle in the early fifth century before Christ. The Roman commander, Aulus Postumius, vowed a temple to the twins if Rome won. Rome did win, and his son later dedicated the temple. Roman tradition placed that dedication in 484 BCE, which makes this one of the oldest temple sites in the Forum.

Now comes the legend. According to the tale Romans told for centuries, two tall young horsemen fought in the front line at Lake Regillus. After the battle, the same two riders appeared here in the Forum. They watered their sweating horses at a nearby spring, announced the victory to the crowd, and then vanished. Romans believed they were Castor and Pollux themselves. It is a legend, not a record. But it shaped this ground for a thousand years.

That spring is still here. Turn a little toward the Palatine Hill, just beside the temple, and look for a small rectangular basin set low in the ground. This is the Spring of Juturna, a water nymph honoured by the Romans. Today it holds a quiet pool, sometimes green, sometimes almost dry. Many visitors never notice it. Yet in the Roman imagination, this modest basin was where gods stopped to rest their horses.

The columns you see are not from that first temple. The building was rebuilt several times. One major rebuilding came in the late second century before Christ. Then, after a fire swept through this part of the Forum, the future emperor Tiberius rebuilt the temple on a grand scale. He dedicated it in the year 6 CE. The three surviving columns belong to this imperial version, carved from white marble in the Corinthian style, the ornate order topped with curling acanthus leaves.

Look closely at the tops of the columns. You can see the leaves, deeply cut, still crisp after two thousand years of rain. Above them runs a fragment of the entablature, the horizontal band that once carried the roof. Architects have studied these few metres of stone for centuries. During the Renaissance, artists came here to sketch the proportions, and many considered this carving among the finest Corinthian work to survive from ancient Rome.

Now lower your eyes to the base. The columns rise from a massive, rough platform of rubble and concrete. Once, this core was faced with stone and marble, and the whole podium stood high above the Forum floor. That height mattered. The front of the temple served as a speaker's platform. Politicians climbed it to address crowds, and stormy public meetings took place right where you are standing. The Senate also met inside the temple on occasion.

Here is something many visitors miss. This was not only a sacred building. It was also a working one. Ancient sources and inscriptions link the temple to the checking of official weights and measures. Small rooms within the podium appear to have held valuables, a little like secure storage. Bankers and traders worked nearby. So picture this temple as both a house of the gods and a place where everyday Roman business carried on beneath the priests' feet.

The twins were also patrons of Rome's cavalry, the class of wealthy riders called equites. Each year, in the middle of July, these horsemen held a grand parade through the city. Ancient writers describe hundreds, even thousands, of riders wearing olive wreaths, and the procession passed by this temple. Imagine the clatter of hooves on the paving, the smell of horses in the summer heat, and the twins' shrine watching over the riders who saw them as their own.

After Rome fell, the temple slowly came apart. Over the medieval centuries, much of its marble was stripped away, burned for lime, or reused in new buildings. Earth and debris buried the Forum floor. For a long time, these three columns stood half-sunk in soil, rising from a field where cattle grazed. That is one reason they became so famous. In a landscape of loss, they were a landmark that people could still recognise.

Take a moment to see the temple's neighbours. Behind you stretches the long base of the Basilica Julia, a great law court. Nearby is the round Temple of Vesta, where sacred fire once burned, and beyond it the remains of the House of the Vestal Virgins. Everything here was packed tightly together. Religion, law, money and politics shared the same few hundred metres of ground, and this temple stood at the centre of that crowd.

Before you move on, stand still and look at the three columns once more. Notice how the light changes on the marble as clouds pass. In the morning it can look almost grey. Late in the day it warms to honey and pale gold. Behind them, the green slope of the Palatine Hill rises toward the old imperial palaces. As you walk away, listen to the gravel again, and remember that horsemen, senators and traders once crossed this same ground.