Tetradrachm
The tetradrachm /ˈtetrəˌdræm/ (Ancient Greek: τετράδραχμον, romanized: tetrádrachmon) was a large silver coin that originated in Ancient Greece. It was nominally equivalent to four drachmae. Over time the tetradrachm effectively became the standard coin of Classical Antiquity, spreading well beyond the borders of the Hellenic world. As a result, tetradrachms were minted in vast quantities by various polities in many weight and fineness standards, though the Attic standard of Athens (about 17.2 grams) was the most common.
Because of their large size, tetradrachms were often used by various states or rulers to advertise themselves or to deliver political messages. Popularity of the tetradrachm outlived the political independence of the Greeks and it remained in wide circulation in the Mediterranean up until Crisis of the Third Century, while debased varieties persisted in India and Central Asia into early Middle Ages.
Often appreciated for their artistic value, tetradrachms are eagerly collected in modern times and well-preserved or rare specimens can reach considerable prices.