Throughout history, Kocaeli has been a gateway connecting Europe with the Middle East and Asia.It was the capital of the ancient kingdom of Bithynia and a crucial trade centre for the Eastern Roman Empire. Today, along the commercially active Black Sea and the Marmara Sea shorelines, Kocaeli boasts 34 ports and industrial facility docks, making it a logistics heaven and a gateway to global markets. The province is a hub for both national and intercontinental routes. It is adjacent to Istanbul, one of the world’s largest metropolitan centres and close to two international airports; Istanbul Sabiha Gökçen(SAW) and Istanbul Ataturk(IST), 45 and 80 km. from the city centre respectively. Only 14 km. away is the Cengiz Topel airport serving purely domestic routes. Kocaeli is home to more than 1,600,000 people and is one of Turkey’s most densely populated cities. This is also the home port for the Turkish Navy, demonstrating the continuing historic and strategic importance of the province in military terms.

Being on the way on one of the most important crossroads of the world combining Asia to Europe, Kocaeli and its surroundings has been an important populated place starting from the pre-historic ages. It has been confirmed that population has been existing in this area since 3000 B.C. Despite of that only a few populated places have been discovered dating back to pre-historic ages.

The major reasons of the discovery of only a few inhabited areas in such a convenient area for settlement are the lack of archelogical studies and the destruction of the signs of history by the inhabiters. Kocaeli and its surroundings that have been inhabited up to date and the limited amount of invesitgations have revealed the earliest human signs at the east of Kefken Kovanagzi and Sarisu on the west and on the Pink Rocks and Cebeci shoulders. Remains discovered at Kovanagzi and Cebeci belong to thesubpaleolitic age, remains from Sarisu belong to mid-Paleolitic Age.

Additional again at the kefken headland firing stones have been found spred widely. The first ruins of a populated place dating back to the analictic age is at Valide kopru tumulus found at yalakdere village of Karamursel. Other signs possibly belonging to a populated place are found at the Cene mountain at the county of Derince. However no detailed investigations have been held at both places. Except these two no other inhabited until the 1800's BC place has been discovered.

First evidences belonging to Kocaeli date back to the 12th Century BC. At these times the Frigs have dominated the area, afterwards a group from the city of megara of greece seeking a new place for themselves have built the city of Astacos at todays area called Basiskele. After the demoliton of Astacos caused by the king of Tracia Lysimakhos on the side reefs of todays Kocaeli a new city called Nicomedia has been built.

At 262 B.C Alexander the Great who has had the city built, his king Nicomedes who was charged with the conquest of Anatolia had named the city with his wifes name. The constantly rising Bythinian Kingdom center Nicomedia, became a big Helenistic city. 91-94 BC it was donated to the Romans. 284 BC emperor Diocletionus has again turned Nicomedia into the capital city. By his time Nicomedia has become the fourth biggest city after Rome, Antakya, Alexandria. At the last quarter of the 11th century Nicomedia has been conquered by the Selchuksr. Then it has been taken back with the 1st crusade and stayed under siege of the Latins, then was recaptured by the Selchuks.

The city has come under control of the Ottomans at Orhan Gazi period with its conquest by Adapazari and Hendek regions governor Akcakoca. At early stages its name Iznikmid which means neighbour of Iznik has changed to Kocaeli in time. Being tied to Istanbul until 1888 Kocaeli became a separate city after this date. Remaining under siege of British and Greek forces during the independence war period the city was liberated at 28th of June 1921, after the announcement of the republic became the center of the Kocaeli province. During the republican times industrial investments to the area have shaped the infastructure of the area and governmental and private investments have multiplied.

Today a developed Industrial city; surrounded by roads and railroads. Beside of that with the Derince and kocaeli ports it has established contact with world maritime lines. Covering somewhat a small surface area, with its production in industrial and value addition it is an interesting example not only for Turkey but also for the world.