Situated on the coast of ancient Propontis (Sea of Marmara), Drepanon was a strategic settlement renamed Helenopolis by Roman Emperor Constantine I in honor of his mother, Helena. Located at the crossroads of maritime trade routes between the Mediterranean and Black Seas, this city also became an important center during the early Christian period.

History

While definitive information regarding Drepanon's foundation is limited, it is believed to have emerged under the influence of Greek colonization in early periods, much like many settlements in the Propontis region. The city's true significance increased during the reign of Roman Emperor Constantine I. In the late 3rd century CE, when Nicomedia (modern İzmit) became one of the eastern capitals of the Roman Empire, Drepanon gained a strategic position due to its proximity to this important center. In the early 4th century CE, Emperor Constantine honored Drepanon, believed to be the birthplace of his mother Saint Helena or strongly associated with her, by renaming it Helenopolis ("City of Helena"). This renaming enhanced the city's political and religious prestige. Helenopolis became an important stop on the route to Constantinople (Istanbul) and, particularly during the Byzantine period, emerged as a significant center for Christianity, even serving as an episcopal see.

Geographic Location

Drepanon/Helenopolis is located in northwestern Anatolia, on the southern coast of the Propontis (Sea of Marmara), at the western end of the Gulf of Astakos (modern İzmit Gulf). The city's coordinates are 40.721717 latitude and 29.502087 longitude. This strategic location made the city a transit point for both maritime and land trade routes. It provided connections eastward to the important Roman and Byzantine city of Nicomedia, and westward via Yalova to other significant settlements such as Prainetos and Prusa. Thanks to its position on the Sea of Marmara, it played a critical role in controlling maritime trade between the Black Sea and the Aegean and Mediterranean Seas. Its surrounding fertile lands and access to the sea contributed to the city's economic life.

Significance in Antiquity

Helenopolis's significance in antiquity was multifaceted. Economically, its location at one of the key points of the Propontis offered a favorable environment for maritime trade and fishing activities. Especially after the foundation of Constantinople, its position on the trade and travel routes to and from this new capital supported the city's economic vitality. Politically, its renaming by Emperor Constantine in honor of his mother bestowed great prestige upon the city and established a direct link with the imperial family. This made Helenopolis an important stop on imperial itineraries. Religiously, due to its connection with Saint Helena, Helenopolis became an important pilgrimage and faith center during the early Christian period. The city gained the status of an episcopal see during the Byzantine period and played a central role in Christian life in the region.

Coinage

No coins from this settlement are recorded in the NumisTR database. While large and autonomous cities or important trade centers typically possessed the right to strike their own coins, Helenopolis's proximity to a major imperial mint city like Nicomedia explains its lack of need for its own coinage. In the region's commercial activities, Roman and Byzantine coins struck at the mints of Nicomedia or Constantinople were likely used.

Archaeological Remains

The prominent and monumental archaeological remains of Drepanon/Helenopolis surviving to the present day are quite limited due to modern settlement and damage over time. However, surface surveys and limited excavations conducted in the region have provided some clues indicating the presence of the ancient city. Specifically, structural remains, ceramic fragments, and foundation traces dating to the Byzantine period have been identified. Given the city's status as an important Christian center, it is probable that remains of churches, chapels, or monasteries could be found. However, at present, there are no distinct structures that can be visited as a large-scale archaeological site. Further archaeological work may bring more of the city's secrets to light.

Today

The ancient city of Drepanon/Helenopolis is located today within the borders of the Altınova district, Yalova Province, Turkey, on the Hersek Peninsula. The ancient settlement area lies beneath modern settlements and agricultural lands. Access can be provided by road from Yalova or İzmit. The region boasts natural beauty with its coastline on the Sea of Marmara, but directly visible remains of the ancient city are quite scarce.