Coins from Bithynia
Bithynia was an ancient region, kingdom and Roman province in the northwest of Asia Minor, adjoining the Propontis, the Thracian Bosporus and the Euxine Sea.

It bordered Mysia to the southwest, Paphlagonia to the northeast along the Pontic coast, and Phrygia to the southeast towards the interior of Asia Minor.

Bithynia was an independent kingdom from the 4th century BC. Its capital Nicomedia was rebuilt on the site of ancient Astacus in 264 BC by Nicomedes I of Bithynia. Bithynia was bequeathed to the Roman Republic in 74 BC, and became united with the Pontus region as the province of Bithynia et Pontus

Bithynia

(1) Chalcedon | Lysimachos c. 250-100 BC
Obverse: Head of the deified Alexander with diadem and Ammon's horns right
Reverse: Athena enthroned left, holding Nike with wreath, transverse spear, resting hand on shield; BAΣIΛEΩΣ / ΛYΣIMAXOY // AΣ / KAΛXA
Ref: Marinescu 115 (O. 44 R. 104) issue ...
(2) Kios 325-300 BC
AE unit Kios
Obverse: head of Mithra right wearing peaked cap
Reverse: Kantharos with two grape vines within wreath of grain; A / K_I
Ref: SNG Copenhagen 382
(3) Prusias II 182-149 BC
AE unit Bithynia
Obverse: Wreathed head of Dionysos right
Reverse: Centaur advancing right, playing lyre; monogram below raised foreleg
Ref: RG 26; SNG Copenhagen 639; HGC 7, 6...