The Kingdom of Bithynia was a flourishing kingdom in northwest Asia Minor founded in the early third century by Zipoetes, chieftain of the Bythyni, a Thracian tribe. The coins of the Bithynian kings depict their regal portraits in a highly accomplished Hellenistic style. Nicomedes IV, the last king of Bithynia, was defeated by Mithridates VI of Pontus, and, after being restored to his throne by the Roman Senate, bequeathed his kingdom by will to the Roman Republic in 74 B.C. The area became a Roman Province with Nicomedia as its capital.