the
Bithynians were an immigrant Thracian tribe. The existence of a tribe
called Thyni in Thrace is well attested, and the two cognate tribes of
the Thyni and Bithyni appear to have settled simultaneously in the
adjoining parts of Asia, where they expelled or subdued the Mysians,
Caucones, and other petty tribes, the Mariandyni alone maintaining
themselves in the north-east. Herodotus mentions the Thyni and Bithyni
as existing side by side; but ultimately the latter must have become the
more important, as they gave their name to the country. They were
incorporated by Croesus with the Lydian monarchy, with which they fell
under the dominion of Persia (546 B.C.), and were included in the
satrapy of Phrygia, which comprised all the countries up to the
Hellespont and Bosporus. But even before the conquest by Alexander the
Bithynians appear to have asserted their independence, and successfully
maintained it under two native princes, Bas and Zipoetes, the last of
whom transmitted his power to his son Nicomedes I., the first to assume
the title of king. This monarch founded Nicomedia, which soon rose to
great prosperity, and during his long reign (278-250 B.C.), as well as
those of his successors, Prusias I., Prusias II. and Nicomedes II.
(149-91 B.C.), the kingdom of Bithynia held a considerable place among
the minor monarchies of Asia. But the last king, Nicomedes III., was
unable to maintain himself against Mithradates of Pontus, and, after
being restored to his throne by the Roman senate, he bequeathed his
kingdom by will to the Romans (74 B.C.). Bithynia now became a Roman
province. Its limits were frequently varied, and it was commonly united
for administrative purposes with the province of Pontus. This was the
state of things in the time of Trajan, when the younger Pliny was
appointed governor of the combined provinces (103-105 A.D.), a
circumstance to which we are indebted for valuable information
concerning the Roman provincial administration. Under the Byzantine
empire Bithynia was again divided into two provinces, separated by the
Sangarias, to the west of which the name of Bithynia was restricted.

The most important cities were Nicomedia and Nicaea, which disputed with
one another the rank of capital. Both of these were founded after
Alexander the Great; but at a much earlier period the Greeks had
established on the coast the colonies of Cius (afterwards Prusias, mod.
Gemlik); Chalcedon, at the entrance of the Bos