Ancient Astakos was an important ancient Greek settlement located at the eastern end of the Sea of Marmara (Propontis), near the modern Gulf of Kocaeli. Colonized by Megarians, this city played a key role in maritime trade between the Black Sea and the Mediterranean due to its strategic location. Also known for its coinage, Astakos was an active player in the regional economy.

History

Astakos emerged on the historical stage as a Greek colony founded by Megarians in the 8th century BCE. Its location at a strategic point on the Propontis ensured that the city gained importance, both commercially and militarily, from its foundation. Maintaining its existence as an independent city-state in its early periods, Astakos came under Persian rule from the 6th century BCE onwards, becoming part of the Achaemenid Empire. Entering the Hellenistic period with the conquests of Alexander the Great, the city frequently changed hands during the Wars of the Diadochi among Alexander's generals. It was particularly a contested area for significant figures such as Lysimachus and Antigonus. Following the death of Lysimachus in 281 BCE and the rise of the Kingdom of Bithynia, Astakos came under the influence of this new regional power. The settlement of Astakos, destroyed by King Nicomedes I of Bithynia in 264 BCE, was shortly thereafter relocated to Nicomedia (modern İzmit), which was founded very close by and became the new capital of Bithynia. Although this event marked the end of Astakos as an independent city, it holds an important place in the historical heritage of the region.

Geographic Location

Astakos was situated at the easternmost tip of the Sea of Marmara (ancient Propontis), on the southern shore of the modern Gulf of Kocaeli, within the boundaries of today's Başiskele district. This geographical position provided the city with a unique strategic advantage. Its location at the intersection of maritime trade routes between the Black Sea straits and the Mediterranean made Astakos both a port city and a commercial hub. To its east lay the interior regions of Bithynia, while to its west were other important cities of the Propontis (Cyzicus, Chalcedon). The city's fertile lands and proximity to the sea also offered suitable conditions for economic activities such as agriculture and fishing. Furthermore, the natural harbor structure of the gulf provided a safe haven for ships. This location reinforced the city's importance in the ancient world.

Significance in Antiquity

The significance of Astakos in antiquity primarily stemmed from its strategic geographical location. Its position on the transit route for ships carrying grain and raw materials from the Black Sea to the Mediterranean made the city a transshipment and trade center. With the establishment of the Megarian colony, Astakos served as a cultural and economic bridge between the Greek world and the interior regions of Anatolia. The city played an active role, particularly in the trade of grain, fish, and forest products. Politically, its subjugation under various empires and kingdoms (Persian, Hellenistic kingdoms, Bithynian) indicates that it was one of the centers of power struggles in the region. The city's military importance cannot be overlooked; its harbor served as a strategic base for navies. However, with the foundation of Nicomedia in 264 BCE and the relocation of the people of Astakos there, the city's independent political and economic significance largely ceased, its role being taken over by the new capital, Nicomedia.

Coinage

Astakos was one of the autonomous cities in antiquity that possessed the right to mint its own coinage, a significant indicator of the city's economic independence and political status. Evidence for the city's coinage generally dates to the late 4th and early 3rd centuries BCE, corresponding to the early Hellenistic period. The coins of Astakos were predominantly struck in bronze, with silver issues being rare. The obverses of the coins typically depicted busts of gods or goddesses, local heroes, or mythological figures. For instance, Astakos, son of Megareus, the founder and legendary hero of Megara, likely appeared on the coinage as the eponymous figure of the city. The reverses, in turn, might feature ship prows, dolphins, fish, or other marine motifs emphasizing the city's connection to seafaring, along with an abbreviation of the city's name (e.g., AΣ). These coins facilitated Astakos's activity in regional trade and represented the city's identity internationally. The iconography of the coinage also provides valuable insights into the city's cultural and religious beliefs.

Archaeological Remains

The extant archaeological remains of Astakos are quite limited, despite the city's historical importance. The primary reason for this is that after its destruction by King Nicomedes I of Bithynia in 264 BCE, the city's population was largely relocated to Nicomedia (modern İzmit), and the area where Astakos stood was subsequently covered by modern settlements. A significant portion of the ancient city's remains, located within the boundaries of the Başiskele district, has either been buried under modern structures or destroyed over centuries. While surface surveys and limited excavations indicate ancient building foundations, pottery fragments, and architectural remains, prominent and extensive ruins of Astakos's magnificent structures are not visible today. Findings from studies in the region typically bear traces of city walls, harbor structures, or public buildings, but these remains are generally fragmentary and do not cover a large area.

Today

The area where ancient Astakos was located is now situated within the boundaries of the Başiskele district, part of Kocaeli Province in Turkey's Marmara Region. Positioned southwest of the modern İzmit city center, on the coast of the Gulf of Kocaeli, this region hosts dense settlement and industrial activity. As the remains of the ancient city lie beneath modern urbanization, there is no distinct archaeological site easily visible to visitors. However, some minor finds potentially belonging to Astakos may be exhibited in regional museums (e.g., Kocaeli Museum). Access to the region is quite easy by road; Başiskele can be reached by public transport or private vehicles departing from İzmit city center.