Tetradrachm

Ainos sat at the mouth of the Hebros River on the Thracian coast, and its tetradrachms from this narrow window — roughly coinciding with the catastrophic Athenian expedition to Sicily — circulated through a region under constant pressure from both Odrysian Thracian expansion inland and Athenian commercial dominance at sea. The city managed to maintain its own silver coinage precisely because it controlled the river trade route into the Thracian interior, a commercial position that gave it leverage no purely coastal polis could claim.

May's die study places #234–236 within a tightly sequenced group, suggesting concentrated production over a short span rather than steady annual output.