Pentonkion: Ancient Bronze Greek Sicilian Coin

Illustrated Specimen Details: Bronze Pentonkion

Example Specimen: Pentonkion, 3rd century BC (Messina, Sicily)

Authority & Heraldry: Issued during the rule of the Mamertines in Messina. The Mamertines were Italian mercenaries originally hired by Agathocles, the Tyrant of Syracuse. Upon his death in 289 BC, they seized power in Messina, marking a significant transitional period between Greek and Roman influence in Sicily. The obverse features the head of Zeus, while the reverse depicts a naked helmeted warrior armed with a spear and a shield. The inscription ΜΑΜΕΡΤΙΝΩΝ (Mamertinon) identifies the authority, and the letter Π serves as a mark of the denomination.

1. ANCIENT GREECE (Sicily, 5th-2nd centuries BC): pentonkion = 5 onkia = 5/12 litra

The name of the pentonkion coin literally translates from Greek as "five onkia" (pente = five, onkia = ounce). In the monetary system of Greek Sicily, the litra served as the standard unit, divided into twelve onkiai. Thus, a pentonkion represented exactly 5/12 of a litra. This fractional system mirrors the Roman approach, where an as was divided into unciae. Just as the Greeks used the pentonkion, the Romans minted the quincunx (5/12 of an as) to satisfy the same mathematical ratio.

History and Significance

The pentonkion holds a unique place in the history of ancient coinage as a representative of the sophisticated fractional bronze systems developed by Greek colonies in Sicily and Southern Italy (Magna Graecia). While earlier pentonkions dating to the 5th century BC were small silver issues often marked by 5 dots, the later specimens, particularly those of the Mamertines in Messina during the 3rd century BC, were substantial bronze coins weighing between 8 and 12 grams.

Role in the Sicilian Monetary System

During the Classical and Hellenistic periods, cities like Syracuse, Akragas, and Himera utilized the litra as their base. To facilitate local market transactions, they developed a complex division system:

• 1/2 litra = hemilitron

• 1/3 litra = trias

• 1/4 litra = tetras

• 1/6 litra = hexas

• 1/12 litra = onkia

• 5/12 litra = pentonkion

This logical, easy-to-calculate system allowed ordinary citizens to conduct daily trade with precision. The pentonkion of the Mamertines is a fascinating example of this evolution; it reflects the turbulent era when the power in Sicily shifted from the Greek tyrants to the rising dominance of the Roman Republic. As Roman influence solidified, these Hellenistic denominations were eventually replaced by the Roman bronze standards, such as the quadrans and the semis, signaling the end of the distinct Greek Sicilian monetary tradition.