Kios, situated on the coast of ancient Propontis, was an important Greek city initially founded by Milesian colonists. After its destruction by Philip V of Macedon in 202 BCE, it was rebuilt by Prusias I of Bithynia and renamed "Prusias ad Mare." Due to its strategic location and port facilities, the city played a significant role in the commercial and political life of the region throughout history.

History

Although the exact foundation date of Kios is unknown, it is believed to have been established in the 7th century BCE by colonists from Miletus, one of Ionia's prominent cities. The city developed in a strategic location on the southern coast of the Propontis, surrounded by fertile lands and possessing a natural harbor. During the Hellenistic Period, in the 3rd century BCE, it joined the Aetolian League in an effort to preserve its independence and political identity. However, this drew the city into the center of regional power struggles. In 202 BCE, it was besieged by Philip V of Macedon and suffered extensive destruction. Following this tragic event, Prusias I, King of Bithynia, undertook the city's reconstruction and renamed it "Prusias ad Mare" (Prusias by the Sea) in his own honor. With the Roman Empire's dominance in the region, the city continued its existence under Roman administration and maintained its importance during the Byzantine era.

Geographic Location

Prusias ad Mare/Kios was situated on the southern coast of the Propontis, known today as the Sea of Marmara, at the eastern end of the modern Gemlik Gulf, where the contemporary district of Gemlik is located. The city's direct access to the sea and its natural harbor made it an important stop on maritime trade routes from antiquity onwards. Its connection with inland regions played a key role in the seaborne transport of products, especially those from Bithynia's fertile agricultural lands. Geographically, Prusias ad Mare is also notable for its proximity to important centers of the Bithynian Kingdom and later the Roman province, such as Nicomedia (Izmit) and Nicaea (Iznik). This strategic location enhanced the city's importance, both commercially and militarily.

Significance in Antiquity

Prusias ad Mare/Kios was one of the leading centers of the region in antiquity, both economically and politically. Thanks to its position on the Propontis, it served as a critical transit point on the maritime trade routes between the Black Sea and the Aegean and Mediterranean Seas. The city functioned as an important port for the export and import of local products, particularly agricultural goods, timber, olive oil, and wine. Politically, its participation in the Aetolian League in the 3rd century BCE indicates that the city was an active player in the political dynamics of the Hellenistic world. Even after coming under the control of the Bithynian Kingdom, it maintained its administrative and commercial significance in the region. During the Roman Empire, the city's port remained one of the crucial points establishing maritime connections with the empire's eastern provinces, contributing to the city's continued economic prosperity. From a religious perspective, in addition to the worship of typical Greek deities, it is believed that local cults specific to the region also existed.

Coinage

Prusias ad Mare is an ancient mint represented in the NumisTR database by 23 coin varieties. The recorded coins were struck in bronze, silver and gold. Authorities named on the coins include Lysimachus and Bitorix. You can browse the city's coins in the Bithynia coins list.

Archaeological Remains

The remains of the ancient city of Prusias ad Mare/Kios are largely buried beneath the modern city of Gemlik. This situation makes extensive and systematic archaeological excavations challenging. However, significant findings related to the city's past have been encountered during occasional surface surveys, rescue excavations, and construction works. Some remains of the ancient theater, sections of the city walls, and artifacts unearthed from necropolis (cemetery) areas offer clues about the city's architectural structure and cultural life. Mosaics, ceramic fragments, inscriptions, and various architectural elements dating to the Roman and Byzantine periods reveal the city's long history of settlement and its prosperity levels during different eras. Although most of the remains are not directly visible today, it is known that a rich ancient heritage lies beneath modern Gemlik.

Today

The ancient city of Prusias ad Mare/Kios is currently located beneath the modern settlement area of the Gemlik district, which is part of Bursa province in Turkey. Gemlik is approximately 30 kilometers from Bursa city center and is easily accessible by road. Since the modern city was built upon the ancient one, a significant portion of the ancient remains lies beneath modern constructions. Visitors wishing to trace the ancient city's footsteps and view artifacts unearthed from the region can visit the Archaeology and City Museum in Gemlik. Gemlik continues to thrive as a vibrant region on the coast of the Sea of Marmara, both touristically and commercially.