iIn Izmit, communities began to live in 3000 BC for the first time. In the 12th century BC, Izmit was started to be managed by the Phrygian state. But in a short period of time, Izmit was conquered by the kingdom of Bithynia. And Izmit was the capital of the Bithynia kingdom.
Izmit was conquered in 94 BC by the Roman State. And Izmit was the capital of the eastern region of the Roman state. For this reason, Izmit was a very important city for the Romans. And by the Romans, a lot of buildings were built in Izmit.
In 1327, the Ottoman Empire conquered Izmit. For a short time, the Byzantine Empire took Izmit back. But immediately after that, the Ottomans began to be managed the 陌zmit again. After the breakup of the Ottoman Empire, Izmit has been a city of the Republic of Turkey.