Roman Sestertius

By Steve Benner for CoinWeek …..

After the denarius, the sestertius is the second most commonly recognized coin of the Roman Empire (27 BCE – 476 CE). Yet little is known of the coin during the Roman Republic (509 – 27 BCE). Parts of this discussion overlap with my previous article, “Ancient Roman Coinage From Republic to Empire”, since there I cover all the denominations. But here, I will go into more detail about the evolution and history of the sestertius.

Reforms of 211 BCE

In 211 BCE during the Second Punic War, Rome decided to make major revisions to its coinage.

In the third century, the Romans had introduced a silver didrachm (6.5 g.) around 269 BCE and then a quadrigatus in 235 that was similar to the didrachm. These were discontinued and replaced with three new silver denominations: the denarius, the quinarius, and the sestertius. These would continue to be minted until near the end of the third century CE. The denarius was valued at 10 bronze asses (4.52 g.) and had an “X” behind the head of Roma on the obverse. The reverse had the Dioscuri, each holding a spear, on horseback riding right with Victory flying to the right holding a wreath and with ROMA below. As shown in Figure 1, all three new denominations were essentially the same style. Aside from differing in weight and having no flying Victory, the main difference was that the quinarius had a “V” on the obverse and the sestertius had an IIS. This meant the quinarius was worth five Asses or half a denarius (2.76 g.), and the sestertius was worth two-and-a-half asses (the “S” in IIS referring to a semis or half as) or a quarter denarius (1.13 g. or one scripulum). The name “sestertius” comes from a contraction of “SEMIS TERTIVS”, which means “half third” or half a third as for two-and-a-half asses.

The reform of the coinage may have been a direct result of the capture and looting of the Sicilian city of Syracuse. The large influx of silver prompted the Romans to start making coins that were uniquely Roman. In addition, three new denominations of gold coins were minted: one each worth 60, 40, and 20 asses. Again, the gold probably came from the loot captured at Syracuse.

Figure 1: 211 B.C.E. Reform coinage: a) Denarius, b) Quinarius, and c) Sestertius. (Figure from my article in CoinWeek). (the Sestertius sold for $2450).

The sestertius was discontinued by 208 BCE. In 200, the denarius was devalued from 72 to 84 denarii per pound of silver (the Roman pound of 12 ounces weighed about 326 grams). This reduced the denarius to 3.96 grams and the sestertius to slightly less than one gram. About the mid-second century, the denarius was revalued at 16 asses, since the as had been reduced in weight. This meant that the sestertius was now valued at four asses, which is what it would stay for the rest of its existence. The sestertius would not be revived until the middle of the first century BCE.

Revival of the Sestertius

About 91 BCE, the silver sestertius made a short-term comeback. Figure 2 shows a second-year issue with an Apollo obverse and a racing horse reverse by the moneyer L. Calpurnius Piso Frugi. It weighs 0.90 grams, which is not far off from the sestertii produced in 200. The coin is not particularly attractive but is rare.

Figure 2: L. Calpurnius Piso Frugi. 90 BCE. AR Sestertius. Rome mint. Laureate head of Apollo right / Bridled horse galloping right, FRVGI,11mm, 0.90 g., Crawford 340/3b. (318, Lot: 516, $900, 1/5/14).

In 47 BCE, the moneyers began to mint sestertii on a more regular basis. This was during the time of Julius Caesar and may have been by his instigation. They are not impressive since the coins tend to be of poor craftmanship, like the one in Figure 2. Two of these later sestertii are shown in Figures 3 and 4.

The first is from 46 BCE by moneyer Mn. Cordius Rufus and weighs 0.63 grams. In Figure 3, the obverse has the head of Venus, and the reverse has a Cupid. This series of coins usually have the head of a deity or a helmet on the obverse, and the reverse varies, though Cupid frequently appears.

The second (Figure 4) is from the moneyer L. Papius Celsus with a Mercury obverse and a lyre reverse and weighs 0.64 grams. The weight of the sestertius seems to have dropped to about two-thirds of its original weight by this time. All of these coins are rare or extremely rare. The minting of the silver sestertius dropped off before the end of the 40s BCE.

Figure 3: Mn. Cordius Rufus. 46 BCE. AR Sestertius. Rome mint. Diademed head of Venus right MCORDIVS/ Cupid advancing right, holding wreath and palm frond RVFVS, 9mm, 0.63 g., Crawford 463/5a. (NG 90, Lot: 1366, $2100, 5/23/12).
Figure 4: L. Papius Celsus. 45 BCE. AR Sestertius. Rome mint. Head of Mercury right, wearing winged petasus; winged caduceus behind; CELSVS downwards to right / Lyre, 10mm, 0.64 g., Crawford 472/4b. (Triton XVI, Lot: 823, $3250, 1/7/13).


In 40, Octavian and Mark Antony signed the Treaty of Brundisium separating the Roman Empire into the Western and Eastern halves. Now in charge of the eastern half of the Empire, Antony introduced a set of six bronzes to be used as small change in Greek Achaea and Asia Minor. He based these upon coins of the Roman Republic, and they included the sestertius, the tressis, the dupondius, the as, the semis, and the quadrans. These are referred to as “fleet coinage” because they were minted by three of Antony’s naval commanders–L. Calpurnius Bibulus, L. Sempronius Atratinus, and M. Oppius Capito–whose names were on the reverse.

The sestertius was transformed from a small silver coin into a large bronze one. This series of coins would become the basis for the Roman Empire’s bronze coins.

Figure 5 shows an excellent example of the sestertius. It was minted by Atratinus around 38 BCE somewhere in the Peloponnesus and is 34 mm in diameter, weighing 22.68 grams. In the reverse field, it has an HS and a D. As mentioned earlier, the IIS is the symbol for a sestertius in the Republic, but now a crossbar was placed across the II, making it look like an H. This coin is very rare, especially in nice condition.

Figure 5: The Triumvirs. Mark Antony and Octavia. Late summer-autumn 38 BCE. Æ Sestertius. Fleet coinage. Uncertain mint in the Peloponese; L. Sempronius Atratinus, auger and consul designatus. M • ANT • IMP • TER • COS • DES • ITER • ET • TER • III • VIR • R • P • C, Bare head of Mark Antony right, facing draped bust of Octavia left / L • ATRATINV[S • AVGVR • COS • DESIG], Two standing figures (Antony and Octavia?) in quadriga of hippocamps right; HS in left field, Δ and astragalus(?) below, 34mm, 22.68 g., Sydenham 1261. (CNG 271, Lot: 45, $12,000, 1/11/12)
Almost simultaneously, Octavian started minting large bronze sestertii. The timing is coincidental since this was at the same time that Antony’s bronze coins were minted. There was probably a need for small change in the Western Empire as well as the Eastern.

There were several styles; one shown in Figure 6 has Octavian on the obverse with the legend “Son of the Divine Caesar”, and Julius Caesar on the reverse with the legend “Divine Julius”. The other style has the same obverse with CAESAR removed, and the reverse has the same legend inside a laurel wreath and no portrait. These two coins were minted in either southern Italy or Gaul and are about 31 mm in diameter and 20 grams weight (this example is a little light).

Figure 6: The Triumvirs. Octavian and Divus Julius Caesar. 38 BCE. Æ Sestertius (or Dupondius?). Southern Italian or Gallic mint. DIVI・F CAESAR, bare head of Octavian right / DIVOS IVLIVS, wreathed head of Divus Julius Caesar right, 30.5mm, 13.42 g., Crawford 535/1. (CNG 555914, $2500).

Also, in the 20s BCE, some cities in Asia Minor began minting “sestertii” with Augustus’ (Octavian’s) portrait. These coins were probably meant to replace the sestertii that had been minted by Mark Antony. They are similar in weight and size to future sestertii.

Roman Empire Sestertii

Circa 18 BCE, Augustus introduced the new orichalcum sestertius. Orichalcum is brass made up of about 80% copper and 20% zinc. The term orichalcum comes from aurichalcum, which means “gold-copper” because of its gold-like appearance when freshly minted. The new brass sestertius was valued at four asses and was around 25 to 28 grams, 32–38 mm in diameter, and about 4 mm thick. Since orichalcum was valued at twice that of bronze, the bronze dupondius was valued at 2 asses even though it was about the same size.

The emperor’s portrait did not begin appearing on sestertii until the reign of Caligula. These early bronze/brass coins were called the “moneyers’ series” because the moneyer’s names were in the reverse legends, a practice that was discontinued by the time of Tiberius. An example is shown in Figure 7, which has CIVIS between two laurel wreaths and OB above and SERVATOS below on the obverse. This legend means “For Saving the Citizens”. The reverse has SC surrounded by a legend describing the moneyer, C. Cassius Celer. The SC refers to Senatus Consultum (“By Decree of the Senate”), since the Senate was put in charge of minting non-precious metal coins.

The mint at Lugdunum (modern Lyon, France) did produce sestertii with Augustus’ profile in its “altar” series.

Figure 7: Augustus. Æ Sestertius. Rome mint; C. Cassius Celer, moneyer. Struck 16 BCE. OB above, SERVATOS below, CIVIS within oak wreath between two laurel branches / C CASSIVS C F CELER III VIR AAA FF around large S • C, 35mm, 23.63 g. RIC I 374. (CNG 42, Lot: 506, $300, 1/14/15).

The coin in Figure 7 seems a little crude, but by the mid-first century CE, the sestertius became one of the most beautifully produced coins in the Roman Empire. The large format gave the engravers room to really demonstrate their skills. Figure 8 shows one of the most famous with Nero on the obverse and the harbor of Ostia on the reverse.

Figure 8: Nero. 54-68 CE. Æ Sestertius 6h). Rome mint. Struck circa 64 CE. laureate head right / Port of Ostia, 36mm, 28.76 g., RIC I 178. (CNG 900743, $24,500).

During the second century CE, the size and weight stabilized at about 34 mm and 25 grams, respectively, but this would shrink in the third century to 20 grams and 25-30 mm by the time of Severus Alexander (ruled 222 – 235 CE). The 20% zinc content would drop to 5% zinc – the result of melting down old sestertii to make new ones. Most of the zinc would boil off and had to be replaced by lead or tin. This made the sestertii much darker in color.

During the reign of Trajan Decius (249 – 251 CE), the emperor introduced the double sestertius; note the radiant crown. This coin did not catch on, except for the Gallo-Roman emperor Postumus (259 – 268 CE), who also minted double sestertii.

Figure 9: Trajan Decius. 249-251 CE. Æ Double Sestertius (Rome mint, 4th officina. 3rd emission, 250 CE. IMP C M Q TRAIANVS DECIVS AVG, radiate and cuirassed bust right / FELICITAS SAECVLI, S C across field, Felicitas standing facing, head left, holding long caduceus with her right hand, cradling cornucopia with her left arm, 35.5mm, 40.07 g., RIC IV 115a. (Triton XXIII, Lot: 826, $2750.

The debasement of the antoninianus to a bronze coin with a silver wash by the time of Gallienus (253 – 268 CE) would lead to the disappearance of the sestertius. Aurelian (270 – 275 CE) minted some much lighter and smaller coins that are referred to as “sestertii”, but the sestertius of Augustus was no longer minted.


The 211 reform sestertii usually run from a couple hundred to thousands of dollars depending on the condition and are readily for sale. The sestertius in Figure 1 sold for $2,450 USD because of its condition. Buying a VF example would not be difficult. They are attractive coins and represent an interesting time in Roman history.

The same can’t be said of the revived sestertius from the late Republic. These coins are crude and not attractive, but it would not be the first time I bought an ugly coin just to say I have one (BTW I don’t have one of these).

The outstanding sestertii are those of the mid-first through the mid-third century CE. These can be real works of art. Some, like the one in Figure 9, can be very expensive, but there are many beautiful ones that are reasonably priced in VF condition.

I have been trying to collect a nice sestertius of each of the Roman emperors, but, since I’m on a limited budget, it means I have trouble getting a rare emperor in VF condition or even getting one of him at all (Gordian I and II). As a result, I do have a few F/G sestertii in my collection that I wouldn’t have bought unless it was to fill a gap in my collection.

* * *


Crawford, Michael H. Roman Republican Coinage. UK: Cambridge University Press (1974)

Hornblower, Simon; Spawforth, Antony (ed.). The Oxford Classical Dictionary. Oxford (1996)

Madden, F.; Smith, C.R.; Stevenson, S.W. A Dictionary of Roman Coins. London (1889)

Sear, David. Roman Coins and Their Values I. Spink (2002)

Vagi, David. Coinage and History of the Roman Empire (2 volumes). Coin World (1999)

* * *

About the Author

Dr. Steve M. BennerSteve M. Benner has a Ph.D. in engineering from the Ohio State University and worked for NASA at the Goddard Space Flight Center in Greenbelt, Maryland, for almost three decades before retiring in 2016. He has been an ancient coin collector since the early 1970s and is a member of the ANS, the ANA, and the ACCG. He specializes in coins of the ancient Greek leagues and in Roman Imperial bronzes. Dr. Benner has published over 30 ancient coin articles in various publications and is the author of Achaian League Coinage of the 3rd through 1st Centuries B.C.E. (2008) and History and Coinage of the Ancient Greek Leagues, 5th through 1st Centuries B.C.E. (2018).


This site uses Akismet to reduce spam. Learn how your comment data is processed.