an ancient kingdom of Asia, formerly known by the names of Mysia, Mygdonia, Bebrycia, Mariandynia, and Bithynia. It was bounded on the west by the Bosporus Thracius and part of the Propontis, on the south by the river Rhyncacus and Mount Olympus, on the north by the Euxine Sea, and on the east by the river Parthenius. The chief cities were Myrlea, Nicomedia, Chalcedon, Heraclea, and Prusa.