Watch List notes:

GREEK COINS
BAKTRIA

Greco-Baktrian Kingdom. Diodotos I, circa 255-235 BC. Stater (Gold, 16mm, 8.23 g 6), in the name of the Seleukid king Antiochos II, mint A (Aï Khanoum area). Diademed head of Antiochos II to right. Rev. ΒΑΣΙΛΕΩΣ ANTIOXOY Zeus Bremetes, seen from behind, advancing to left; his extended left arm draped with an aegis, and preparing to hurl thunderbolt with his right hand; in inner left field, N above eagle standing left. Bopearachchi -. Cf. Holt Series A, Group 7 (tetradrachm). SC 629. SNG ANS -. A most attractive example without the typical test cut on the obverse. Good very fine.

From the collection of a Swiss traveler, ex Classical Numismatic Group 85, 15 September 2010, 550.
The Baktrian kingdom was founded by Diodotos I who had been appointed satrap of Baktria by Antiochos II, but who then revolted in 255. He seems to have ruled jointly with his son Diodotos II from 246 until his death in 239. The revolt was, however, rather gradual since the coinage produced by Diodotos I first bore the portrait and name of Antiochos II and then continued in the name of the Seleukid king but with his own somewhat elderly looking portrait.