Bithynia

District of northwestern Asia that became a Roman province 74 BC, and was from 64 BC administered with part of Pontus. One of its most famous governors was Pliny the Younger in the reign of the emperor Trajan. A number of his official despatches to Trajan survive in Book X of Pliny's Letters. Nicaea was one of its chief cities.

Bithynia was bounded in the north by the Propontis, Thracian Bosporus, and Black Sea; in the east by Paphlagonia; in the west and southwest by Mysia; and in the south by Phrygia and Galatia. Occupied at an early date by Thracian tribes, it was included in the empire of Lydia, and in that of Persia 546 BC. In the 4th century BC it became an independent kingdom (capital Prusa) under native princes and remained so until the death of Nicomedes IV 74 BC, who bequeathed it to Rome.