Oldest dated coin

The earliest dated coin is a Samian silver tetradrachm struck during the occupation of Zankle (now Messina), Sicily, dated year 1, viz 494 BC - shown as the letter 'A' on one side. In this particular case, the letters (ranging from A to E) mark the five years (494/3–490/89 BCE) that exiles from Samos held the city.

The earliest-known Christian Era dated coin is: MCCXXXIIII (1234) Bishop of Roskilde coins, Denmark (seven known). There are even earlier coins from this period are known to be dated, but in different calendars. An example includes a silver obol struck in Toledo. While the date is given as "1166," it uses the "Hispanic Era" dating system that was used throughout the Iberian Peninsula in the Middle Ages. On the Christian calendar, this coin was actually struck in 1204—thirty years before the coins in Denmark.