Many clues help narrow down the date ranges of coins minted more than 2,000 years ago
At NGC Ancients, often we are asked: How do we know when an ancient coin was struck? This is a fundamental question for ancient Greek coins, on par with identifying who issued a coin.
For many coins, it is possible only to estimate when it was struck based on hoard evidence, style and fabric (physical characteristics), or historical context. Often, this means a date may only be narrowed down to a particular century or two.
This bronze of Cyzicus, in Mysia, is attributed to the 2nd through the 1st Centuries BCE. All images courtesy of Classical Numismatic Group (CNG) and NGC
Luckily, during Hellenistic times, when most formerly independent Greek cities had fallen under the authority of monarchs, the practice of placing dates on coins became commonplace in the eastern part of the Greek world.
Cistophorus of the city of Ephesus dated year 33 (101/100 BCE)
These are not dates that a modern collector will be familiar with, so you won’t see a coin explicitly dated 100 BCE or 100 CE. Instead, dates are rendered based on a known era, principally the era of a kingdom, a particular ruler or an event, such as when a city achieved its independence.
Many era dates are used, but the most common is that of the Seleucid Kingdom, in which year 1 was 312 BCE, when the kingdom’s founder, Seleucus I, took possession of Babylon. The Seleucid era was so popular that it was used in other kingdoms, and even was used long after the Seleucids had left the scene.
Tetradrachm of the Seleucid king Alexander Balas dated to Seleucid Era year 164 (149/8 BCE)
Tetradrachm of the Parthian king Gotarzes II dated to Seleucid Era year 358 (47/8 CE)
Other popularly used eras include the Actian (year 1 being 31 BCE, when Marc Antony was defeated by Octavian at the Battle of Actium), the Pompeian (year 1 being 64 BCE) and the Caesarean (year 1 being 49 BCE, though sometimes it is considered to be 48 or 47 BCE).
A Nabataean drachm of King Malichus I, dated year 28 (33/2 BCE)
Foundation dates are also popular, with “year 1” being the year in which a city was founded or regained its freedom.
For the most part, regnal dates were used in Egypt under the Ptolemaic dynasty, and with the long series of Roman provincial coins issued at the mint of Alexandria. Though various numbering systems were used to represent the regnal years, the most common was the use of Greek letter(s) with known translations into numbers.
The numbers in such systems are additive, reading from either left to right, or right to left. The table below illustrates the correlations.
Using this system, a coin of year 100 would be dated with just a P, whereas one of year 101 would be dated PA, and one issued in year 152 would be dated PNB.
The city of Tyre began dating their coins fairly early. The earliest of these use a series of Phoenician symbols to represent the dates, whereas the later shekels and half shekels use the Greek letters shown on the table above, with year 1 starting in 126/5 BCE.
Didrachm of the city of Tyre dated to year 7 of the reign of its ruler Azemilkos
Shekel of Tyre dated to year 171 (45/6 CE)
The Ptolemaic Kings of Egypt used regnal years to date their coins, with each king starting the cycle over again at year 1. Ptolemaic dates are proceeded by the demotic letter L.
Tetradrachm of the Ptolemaic king Ptolemy VIII dated year 32 (139/8 BCE)
The Ptolemaic system is relatively hard to decipher since most every dated silver coin uses the same design formula (portrait of the founder-king, Ptolemy I, and a standing eagle), and the coins often look quite similar from king to king, with there being only subtle differences in style and fabric that require intensive academic study to decipher.
This double-dated tetradrachm of the Ptolemaic queen Cleopatra III and King Ptolemy X records year 12 of Cleopatra III and year 9 of Ptolemy X, equating to 106/5 BCE
Other dating styles were used by various kingdoms. Some used the Greek alphabet with the letters Alpha through Omega representing the numbers 1-24 consecutively. Some cities used Phoenician symbols, and the Nabataeans used their own numbering system.
Tetradrachm from the city of Aradus, using types introduced nearly a century earlier by the Macedonian king Alexander III, dated (in Phoenician letters) to year 24 (236/5 BCE)
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