Stater

Karthaia occupied the southeastern coast of Keos, one of the Cycladic islands closest to Attica, and its coinage emerges in the late Archaic period when several Kean cities were producing independent issues simultaneously. The stater type referenced under HGC 6, 540 belongs to an early phase of that civic output, predating the political consolidation that would eventually bring the island's poleis into closer alignment with Athenian interests after the Persian Wars.

Keos as a whole fell under Athenian influence by the mid-fifth century, and the independent coinage of its constituent cities grew increasingly rare thereafter.