Roman Currency

Units of Currency

The Rise of the As

The Roman as was, at first, a specific weight: one pound of bronze

This pound was divided into twelve unicae (ounces)

Please note, the noun (3rd / m.) declines as follows:

  • as, assis, assī, assem, asse
  • assēs, assium, assibus, assēs, assibus

Introduction of Silver Coinage

During the Republic (late third century BCE), two new coins were introduced: the dēnārius and the sēstertius, these made of silver

One sēstertius was valued at 2.5 assēs, and one dēnārius at 10 assēs

“The sēstertius was probably introduced at a time when the as had been so far reduced that the value of the new coin was equivalent to the original value of the as.” (AG, 633)

  • Debasement was a persistent threat to Roman coinage

During the early Empire, a gold coin, the aureus, was introduced, at the value of 100 sēstertiī

Height of the Sēstertius

The sēstertius became the common coin of the Roman Republic and Empire

  • Where Roman authors say nummus, coin, they typically mean sēstertius

The word, sēstertius, is an elision of sēmis-tertius, ‘the third a half’

  • Picture the Romans counting three assēs, the third of which is at half value, for a total value of two and a half

Sēstertius vs. Sēstertium

The sēstertium was a unit of value, not a coin, equivalent to 1,000 sestertiī

  • It likely derived from the genitive plural in the phrase mīlle sēstertium 


The sēstertius could be cataloged as HS or HS, a confusing symbol until one considers its evolution

  • The symbol began as IIS (viz. 2S), or duo et sēmis, two and a half, and the H became standard somewhere along the way

Where a line appears above an abbreviated sum, it indicated thousands

  • The sum HS CC = 200 sēstertiī, but the sum HS ̅c̅c̅  = 200,000 sēstertiī, or 200 sēstertia 

Roman Wages

Sampled from the end of the Republic, consider and compare these wages

  • A typical legionary was paid 900 sēstertiī per annum
  • A day-laborer might make 3 sēstertiī per dīem 
Review of Values

aureus = 25 dēnāriī = 100 sēstertiī = 250 assēs

dēnariī = 4 sēstertiī = 10 assēs 

sēstertius = 2.5 assēs

as = an ever-decreasing weight of bronze (or, later, of copper)

sēstertium = 1 mīlle sēstertium = 1,000 sēstertiī 


The Essential AG: 632


Famous Phrase: crescit amor nummī quantum ipsa pecūnia crēvit

(love of money grows as much as money itself is known)

-Juvenal, Satires, 14.139