Nicomedia

Nicomedia (; Greek: Νικομήδεια, Nikomedeia; modern İzmit) was an ancient Greek city located in what is now Turkey. In 286 AD, Nicomedia became the eastern and most senior capital city of the Roman Empire (chosen by the emperor Diocletian who ruled in the east), a status which the city maintained during the Tetrarchy system (293–324 AD).