During my guided tours, I often mention that Mediolanum (now Milan), like Nicomedia (now İsmet, Turkey), Trier (Germany), or Sirmium (now Sremska Mitrovica, Serbia), was once a Roman imperial capital. This fact often astounds my listeners.
Milan, or rather, Mediolanum, became the capital of the Western Roman Empire in 286 AD. This period saw the vast Roman Empire begin to experience some “managerial” problems. For this reason, Emperor Diocletian decided to divide the imperial territories into two large areas, one west and one east of Rome, and to enlist the aid of another emperor and two “deputies” who would take over the emperor’s place upon their deaths. Thus was born the tetrarchy, a divided command (a power of four), in which two emperors, called Augusti, coexisted with two deputies, called Caesars, each with their own capital.
Diocletian chose Maximian Eurculeus (his trusted and valiant general) to serve as his Western alter ego. Maximian, in turn, selected Mediolanum as the main seat of his court.
Maximian recognised Mediolanum’s strategic value. This once-quiet town, founded by the Celts centuries before, lay near the main mountain passes and at the junction of vital Roman roads—ensuring swift travel and control. Mediolanum’s model citizens enjoyed fine public buildings, including a theatre, an arena, and a forum with temples. Strong walls protected the city, which Maximian would later enlarge and restore.
The emperor commissioned a circus—a stadium for chariot races and public spectacles—his imperial palace, a horreum (food storage facility), and impressive thermae called the Herculean Baths, which were central to Roman social, hygienic, and fitness life for all classes.
A few years after Maximian’s initiatives, another major emperor chose Mediolanum for his daughter Constance’s wedding. In 313 AD, he signed a document guaranteeing freedom of worship to all inhabitants of the empire. The emperor was Constantine, and the document was the Edict of Milan, also known as the Edict of Constantine.
Poet Ausonius praised Mediolanum, calling it wonderful, wealthy, and elegant.
Now I anticipate your question—the one all my guests ask about ancient Roman Milan: “Emanuela, where are the remains of those buildings?”
You’re right, where did ancient Mediolanum go? Milan is a city to be discovered—introverted, revealing its beauty to careful observers. The remains of the ancient imperial city surround us, often unnoticed. Beneath Piazza del Duomo, there’s much to see in the cathedral’s archaeological area or along the subway mezzanine. The Chamber of Commerce and the Stock Exchange stand above the Roman theatre. Under the Church of San Sepolcro are the remnants of the Roman forum. Behind the archaeological museum, the ancient circus, city walls, and a watchtower await discovery.
