Kocaeli history

The history of the modern city of Kocaeli is rooted in deep antiquity, a time when it was known as Nicomedia — one of the greatest metropolises of the ancient world. This city has witnessed the rise and fall of empires, leaving behind a rich cultural and architectural heritage.

Foundation and First Mentions

The initial settlement on this site, called Astacus, was founded as a colony of the Greek city of Megara as early as 712 BC. After its destruction, the city was rebuilt in 264 BC by the Bithynian King Nicomedes I and was named Nicomedia in his honour. It soon became the capital of the flourishing Kingdom of Bithynia.

Key Factors of Formation

The city owes its rise to several key factors:

• Strategic Location: Nicomedia was situated at the intersection of vital trade routes connecting Asia Minor with the Balkans and had access to the Sea of Marmara, making it a major commercial and transport hub.
• Political Significance: In 74 BC, the city came under Roman rule, becoming the capital of the Roman province of Bithynia. Nicomedia reached its peak influence in 286 AD when Emperor Diocletian made it the eastern capital of the Roman Empire.

Early Cultural and Economic Features

During the Roman and early Byzantine periods, Nicomedia was not only an administrative but also a cultural centre, referred to by contemporaries as the "Athens in Bithynia". The city was famous for its magnificent palaces, temples, and public buildings. It was a major centre of craftsmanship and played an important role in the early history of Christianity, becoming the site of martyrdom for many saints, including Saint George and the Great Martyr Panteleimon. Even after the capital was moved to Constantinople, Nicomedia retained its importance as a vital trade and cultural city. In 1337, the city was conquered by the Turks and eventually received the name Izmit, while the province became known as Kocaeli.

Key Milestones in Kocaeli's History

The history of the city, known in antiquity as Nicomedia and today as Kocaeli (and its centre, Izmit), spans nearly three thousand years. It was one of the most important metropolises of antiquity, a capital of empires, and a witness to great events.

Antiquity and the Roman Era

• 712 BC — The first settlement named Astacus is founded, becoming a colony of the Greek city of Megara.
• 264 BC — The Bithynian King Nicomedes I rebuilds the destroyed city and gives it his name — Nicomedia, which becomes the capital of Bithynia.
• 74 BC — Nicomedia, along with the entire Bithynian Kingdom, comes under Roman rule and becomes the main city of the Roman province.
• 286 AD — Emperor Diocletian makes Nicomedia the eastern capital of the Roman Empire, marking the peak of its power and influence.
• 303 AD — The city becomes one of the centres of the Great Persecution of Christians; Saint George and Saint Panteleimon suffered martyrdom here.
• 330 AD — Constantine the Great moves the capital to nearby Byzantium (future Constantinople), after which the political significance of Nicomedia gradually declines.
• 358 AD — A devastating earthquake causes serious damage to the city, which was, however, eventually restored.

Byzantine and Ottoman Period

• 1078 — The city is captured for the first time by the Seljuk Turks, although it later returns to Byzantine control.
• 1299 — The forces of Osman I invade the territory of Nicomedia, which is considered one of the key dates in the foundation of the Ottoman State.
• 1337 — After a long siege, the city is finally conquered by the Ottoman Sultan Orhan I and becomes part of the Ottoman Empire.
• XIV-XV Centuries — The city gradually loses its Greek name Nicomedia and becomes known as Izmit, while the surrounding region receives the name Kocaeli.

Modern and Contemporary Era

• Early 20th Century — Izmit develops as an important industrial and port centre of the Ottoman Empire, and subsequently the Turkish Republic.
• 17 August 1999 — One of the most destructive earthquakes in Turkey's history occurs in the region, leading to significant devastation and loss of life in Izmit and its surroundings.
• Early 21st Century — The city and the province of Kocaeli recover and become one of the largest industrial and economic centres of modern Turkey.

Stages of Formation: From Imperial Capital to Industrial Heart

The development of Kocaeli (historical Nicomedia and modern Izmit) is a journey from an ancient metropolis to the major industrial hub that Turkey takes pride in today. Each era has left its mark on the street layout, economic structure, and culture of the region.

• Transformation into an Imperial Capital (286 AD)
  Emperor Diocletian's decision to make Nicomedia the eastern capital of the Roman Empire launched massive urban planning transformations. Monumental palaces, a hippodrome, baths, and armouries were erected in the city. This laid the foundation for the city as an administrative and cultural centre of global significance.
• Establishment of the First Ottoman Shipyard (XIV Century)
  After the Ottoman conquest of the region, the empire's first shipyard was established here in Karamürsel. This event defined the maritime character of the city for centuries to come, turning it into a key naval base and shipbuilding centre, which fostered an influx of craftsmen and the development of trades.
• Launch of the Anatolian Railway (1873)
  The laying of the railway line connecting Haydarpaşa (Istanbul) with Izmit became a powerful economic driver. The city's railway station turned into a vital transport hub, drastically increasing the port's trade turnover and accelerating the region's integration into international trade.
• Opening of the SEKA Paper Factory (1936)
  The launch of the country's first paper production combine became a symbol of the young Republic's industrialisation. The factory was not just a plant but a city-forming social project: residential quarters, parks, cinemas, and sports clubs were built around it, shaping the modern urban way of life.
• Industrial Boom and Automotive Industry (1960–1970s)
  The establishment of major automotive factories and oil refineries (Tüpraş) in the region radically changed the economic landscape. The city became a magnet for internal migration, leading to the rapid expansion of residential zones and transforming the province into the country's "industrial heart".
• Urban Reset after 1999
  The tragic earthquake became the starting point for a new urban planning policy. Authorities revised the master plan, initiating active development on seismically stable hills instead of the coast. This led to the creation of new safe neighbourhoods, the reconstruction of embankments, and the emergence of modern public spaces.
• Technological Transformation (21st Century)
  The opening of the Osmangazi Bridge and the creation of the "Informatics Valley" (Bilişim Vadisi) marked the transition from exclusively heavy industry to high technologies and logistics. These projects have strengthened the city's status as an innovative hub connecting Europe and Asia.

Architectural Appearance and Urban Development

The architecture of Kocaeli is a complex mosaic intertwining the grandeur of ancient Nicomedia, the refinement of Ottoman architecture, and the pragmatism of the modern industrial era. Due to the high seismic activity of the region, the city has been rebuilt multiple times, forming its unique eclectic appearance: here, ruins of Roman fortifications may stand alongside 20th-century factory chimneys and the latest earthquake-resistant complexes.

Historical Eras and Dominant Styles

The urban fabric of the city has been formed over millennia, and each period has left its mark on the style of the buildings:

• Antiquity and Roman Period (Roman Classicism)
  In the era when the city was the eastern capital of the Roman Empire, monumental order architecture prevailed. Although earthquakes destroyed most structures, surviving fragments of fortress walls, aqueducts, and cisterns testify to the grandiose imperial scale and regular street planning of that time.
• Ottoman Period (Classical Ottoman Style, Baroque, Empire)
  From the 16th century, the city's appearance began to be defined by domed mosques and complexes (külliye). In the 19th century, under the influence of Westernisation, European styles — Baroque and Neoclassicism — penetrated the architecture, vividly manifested in administrative and palace buildings. Civil construction was represented by traditional wooden houses.
• Republican Period and Modernity (Industrial Modernism, High-Tech)
  In the 20th century, Turkey bet on industry, leading to the appearance of functionalist architecture in the city: factory buildings, workers' towns, and wide transport arteries. The modern stage is characterised by the revitalisation of industrial zones and the creation of public spaces in the style of postmodernism and eco-urbanism.

Landmark Buildings and Districts

Several key objects serve as architectural landmarks and reflect the spirit of their time:

• Pertev Pasha Mosque (Yeni Cuma) — An outstanding example of the Classical Ottoman style of the 16th century. Designed by the great architect Mimar Sinan, it is distinguished by the harmony of its proportions and the monumentality of its single dome.
• Izmit Clock Tower — An elegant symbol of the city in the Neoclassical style with Empire elements. Built in 1901 for the jubilee of Sultan Abdul Hamid II, it demonstrates the influence of European clock culture on the Ottoman tradition.
• Hunting Palace (Kasr-ı Hümayun) — A rare example of palace architecture outside Istanbul. The building combines features of Ottoman Baroque and European style, standing out with painted ceilings and a marble façade.
• Historic Quarter of Kapanca Sokak — A reserve of traditional residential architecture of the 19th century. Wooden mansions with bay windows and overhanging eaves have been preserved here, forming the cosy atmosphere of the old city.
• SEKA Park — An example of modern renovation and adaptive reuse. The territory of the giant paper combine was transformed into a landscape park, where industrial objects became part of the cultural environment.

Notable Figures Associated with Kocaeli

Throughout its rich history, the city, known as Nicomedia and now as Kocaeli (Izmit), has been the birthplace and centre of activity for many prominent figures — from ancient philosophers and Christian saints to Ottoman commanders and modern politicians.

• Arrian (Lucius Flavius Arrianus) — Ancient Greek historian and philosopher (c. 86/89 – after 146/160 AD). A native of Nicomedia, Arrian is one of the most important sources on the history of Alexander the Great's campaigns. His main work, "The Anabasis of Alexander", is considered a classic of military historiography. He also held high posts in Roman service and was a student of the Stoic philosopher Epictetus, whose lectures he recorded.
• Saint Panteleimon — Christian Great Martyr and Healer (late 3rd – early 4th century). Panteleimon was a court physician in Nicomedia during the time of Emperor Maximian. After converting to Christianity, he treated all sufferers free of charge, for which he was subjected to severe torture and executed during the Great Persecution of Christians under Diocletian. Today he is revered as one of the most famous saints and the patron saint of doctors.
• Diocletian — Roman Emperor (reigned 284–305 AD). Although not a native of the city, his name is inextricably linked with the history of Kocaeli. In 286, Diocletian made Nicomedia the eastern and main capital of the Roman Empire, turning it into a grandiose metropolis with palaces, temples, and an arsenal. It was from here that he governed the eastern part of the vast empire and initiated one of the harshest persecutions of Christians.
• Kara Mürsel Alp — Ottoman military commander (14th century). One of the companions of the founders of the Ottoman Empire, he is considered the first admiral (Kapudan Pasha) of the Ottoman fleet. By order of Sultan Orhan I, he founded the first Ottoman shipyard in the region, which today bears his name — Karamürsel, and played a key role in the conquest of these lands.
• Turan Güneş — Turkish politician and academic (1921–1982). Born in Kandıra (Kocaeli province), he was a prominent statesman. He served as Turkey's Minister of Foreign Affairs during the Cyprus Crisis of 1974, and his famous phrase "Ayşe can go on holiday" became the code signal for the commencement of the military operation.
• Meral Akşener — Turkish politician (born 1956). A native of Izmit, she is one of the most influential women in modern Turkish politics. She served as Minister of the Interior, was Deputy Speaker of the Parliament, and in 2017 founded and led the Good Party (İYİ Parti).
• İbrahim Çelikkol — Turkish actor and former model (born 1982). Born in Izmit, Çelikkol is one of the most popular and recognisable actors in modern Turkish cinema and television. He has played lead roles in many successful series and films, including the historical drama "Fetih 1453", where he performed the role of Ulubatlı Hasan.