The most popular of all ancient coins is the silver tetradrachm of Athens, also known as the "Owl".
The coin of Athens was the most respected throughout the Mediterranean and other parts of the world, since the city, unlike others, refused to debase it (lessen the amount of silver within) for centuries. Tetradrachms were always near 17 grams (270 grs.) of pure silver.
Nine million "owls" were struck over three centuries. Most were struck between 449 BC and 413 BC, and were used to finance grandiose building projects. (This was the coin used in paying the workers who built the Parthenon, the construction of which ran from 477 BC to 432 BC.) Also, many were used to cover the costs of the disastrous Peloponnesian War, which began between Sparta and Athens in 433 BC, and ended with financial ruin for the Athenian state in 405 BC.
Early versions of this coinage had the "reverse" with the archaic head of Athena in a plain battledress helmet, with the "obverse" displaying her owl, a sprig of olive in the upper left, and the Greek letters for Athens:
right of the owl. However, in 490 BC, the decisive Battle of Marathon occured, and some additions to the design were made. (This battle between the outnumbered but victorious Athenians and the attacking Persians resulted in peace with their main enemy, and an increase in Greek influence over much of the ancient world.) Symbols of peace and victory were added to the coinage in the form of olive leaves on the helmeted Athena. Also, a waning moon in the field above the owl was added, for the night of the battle had a crescent moon; although Sparta was asked by Athens for assistance during the battle, due to religious laws they refused to help until the moon was full. This symbol was perhaps to show the world Athens' achievement without outside help.
This coin was the first to incorporate the "heads" and "tails" configuration which has since become a world standard.
President Theodore Roosevelt carried one at all times in his pocket to remind him of the artistic excellence of the Greeks. This also inspired him to press for a Greco-style redesign of many of our coins, particularly the Saint-Gaudens Double Eagle.
In spite of the large quantities produced, the coin is still not inexpensive. Circulated examples may be found for a few hundred dollars, to nearly $1,000 for beautiful specimens.