Corinth was the first Greek city-state to successfully launch a rival coinage that competed with the Aeginetan standard. The beginning of coinage in Corinth gives some credence to the theory that geography is a determinant of history. The harbor of Corinth stood astride the isthmus connecting Peloponnesus with Attica, looking east toward Aegina, the birthplace of Greek coinage, and west, toward Italy and supplies of silver that it could control. Aegina controlled eastward trade into the Aegean Sea, but to the west the Corinthian gulf opened into the Ionian and Adriatic Seas, giving Corinth a free field to establish colonies on the route to the Adriatic and across the sea to Sicily. Corinth learned about coinage from its eastward trade, and from control of the western sea routes won access to the silver mines of the Illyrian Mountains, breaking the Aeginetan monopoly on Greek supplies of silver.
Corinthian coinage may have been born of a political revolution that displaced an aristocracy and empowered the merchant classes. The first coinage in Corinth roughly coincided with the ascendancy to power in 655 b.c. of Cypselus, who established himself as a despot favoring the merchant classes. Corinthian coinage probably began as a measure to promote the commercial interests of Corinth.
Because it had to transport silver from long distances, Corinth could not coin silver on terms comparable to Aegina. Whereas the Aeginetan silver drachma weighed 96 grains, the Corinthian silver drachma weighed 43 grains, giving the coins of Aegina a sizable edge in Greece and the Aegean trading area. In Sicily and southern Italy, however, the advantage lay with the Corinthian coins that could be shipped directly from the Corinthian Gulf, whereas shipments from Aegina had to round the Peloponnesus, a longer, more dangerous, and therefore more expensive route.
In style and craftsmanship, Corinthian coins utterly outshone the Aeginetan coins. First, they bore the image of Pegasus, the winged horse of Greek mythology, a more charismatic and spirited concept than the clumsy tortoise image on Aeginetan coins. Also, the Corinthians stamped both sides of their coins and designed different coins for various denominations—another departure from the practice of Aegina, which stamped coins of all denominations only on one side and with the same image. In Aeginetan coinage, different coin sizes represented different denominations, a source of confusion to people in distant lands unfamiliar with Aeginetan weights and standards. One side of Corinthian coins always bore the image of Pegasus, but the reverse side bore different images for different denominations. The head of Athena was stamped on the reverse side of the stater, and the head of Aphrodite on the reverse side of the drachma.
The colonies of Corinth adopted the Corinthian coinage system, and sometimes restamped the Corinthian coins with images of their own choosing. Coins have been found upon which the second stamping left vestiges of the original Corinthian stamping. The Corinthian coinage was edging out the Aeginetan coinage when Athens began its own coinage during the sixth century b.c. Athenian coinage would supersede the Aeginetan coinage and substantially overshadow the Corinthian coinage.