The tetradrachm (Greek: τετράδραχμον, transit. 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 Antiquity, spreading well beyond the borders of the Greek World. As a result, various polities (city-states) minted tetradrachms in vast quantities in many weight and finesse standards. However, the Athens-derived Attic standard of about 17.2 grams was the most common.
The tetradrachm's use as a currency was soon adopted by many other city-states of ancient Greece, Asia Minor, Magna Grecia, and other Greek colonial cities throughout the Mediterranean Sea. With the armies of Alexander the Great, it spread to other Greek-influenced areas of Asia.
Because of their large size, various states or rulers often used tetradrachms to advertise themselves or deliver political messages. The tetradrachm's popularity outlived the Greeks' political independence and remained widely circulated in the Mediterranean until the Crisis of the Third Century. At the same time, debased varieties persisted in India and Central Asia into the early Middle Ages.
