Watch List notes:

ATTICA. Athens. Circa 449-404 BC. Tetradrachm (Silver, 25 mm, 16.85 g, 7 h), c. 440-430 BC. Head of Athena to right, wearing crested Attic helmet with palmette and three olive leaves. Rev. ΑΘΕ Owl standing right, head facing; behind, olive spray and crescent moon; . Dewing 1596 ff. Svoronos pl. 13, 21 ff. On the obverse, test pit and an uncertain countermark on Athena's cheek; on the reverse, countermark of an aramaic M to right, otherwise, good fine.
From a European collection formed before 2010.

While struck in the 3rd quarter of the 5th century, this Athenian tetradrachm had circulated for quite a long time prior to being countermarked, probably during the 1st quarter of the 4th century, or even down into the mid century.