in Ancient Geography, a metropolis of Bithynia, built by Nicomedes the grandfather of Prusias. It is situated on a point of the Sinus Aflacenus (Pliny); named the Beautiful, (Athenæus): the largest city of Bithynia, (Paulianas), who says it was formerly called Aflacus; though Pliny distinguishes Aflacus and Nicomedia as different cities. Nicomedia was very famous, not only under its own kings, but under the Romans: it was the royal residence of Diocletian, and of Constantine while Constantinople was building, if we may credit Nicephorus. It is still called Nicomedia, at the bottom of a bay of the Propontis in the Hither Asia. E. Long. 32°. N. Lat. 41°. It is a place of consequence; carries on a trade in silk, cotton, glads, and earthen ware, and is the see of a Greek archbishop.