Euboia was a greek district on an island in the agean sea. The concept of an island being considered in the “central” area of an empire is an odd one, but the territory surrounding the sea and land was all considered greece.
Histiaia was on the northern tip of the island, and did not begin producing coinage until the mid fourth century bc.
From its exteniive silver issues in the hellenistic age it would appear to have been a place of considerable commercial importance. Its ultimate destiny, as with most of the earliest Greek colonies, was to be assimilated into other, larger, societies through conquest.