The Ridge and the Milion

The ridge of the promontory was the central line of high ground in ancient Constantinople. One of the most important landmarks on this ridge was the Milion, the milestone from which all distances in the Roman Empire were measured. It stood just southwest of Hagia Sophia (St. Sophia) and marked the location of an old gate of Byzantium. This area served as a key reference point in the layout and measurement of the ancient city.

Fortifications from the Milion

From the Milion, the ancient city wall continued toward the twisted columns of the Tzycalarii. Based on the direction of the wall, historians believe these columns were located on the plateau near St. Irene, another important Byzantine church. From there, the wall sloped downward to the Sea of Marmara, near today’s Seraglio Lighthouse at a place once called Topi.

After reaching the sea, the wall turned north and ran along the shoreline, encircling the tip of the historic peninsula. Along the way, it passed the areas where the Thermae of Arcadius (public baths) and the Mangana Palace complex were later built.

The Early Size of Byzantium

According to two Byzantine historians, Anonymus and Codinus, this wall described the full circuit of Byzantium from its original foundation by Byzas (the legendary founder) all the way to the reign of Constantine the Great. However, their claim is not entirely accurate. In fact, archaeological and historical evidence shows that Byzantium’s walls enclosed a much larger area than the circuit they describe, especially by the year 196 AD, and perhaps even earlier.

Therefore, their description of the city’s size likely refers only to a very early stage in Byzantium’s history—possibly before it grew into an important regional and imperial center.

Strategic Locations Near the Wall

Historical sources help us locate certain buildings that once stood along this early wall. For example, the Strategion, a military training field like a parade ground, was located at the foot of the Second Hill, close to today’s Sirkeci Station. It was near the granaries by the Prosphorion Harbor, which were close to the Neorion (Bâb-ı Ali Gate)—a site once destroyed by fire Sofia Daily Tours.

Nearby was the Chalcoprateia, or Brass Market, situated close to the Great Basilica and the Yerebatan Cistern (Basilica Cistern), which still exists today. These landmarks help us better understand how the ancient wall of Byzantium shaped the life, trade, and defense of the city.