Coin Relief 8 – The Siliqua

Here is the next edition in a series of blog posts written by Dr. Sam Moorhead and Dr. Andrew Brown, the PAS Finds Advisers for Roman and Iron Age coins.

The Siliqua

In c.AD 323-325 Constantine I reintroduced silver coinage that experienced widespread usage throughout the 4th and into the 5th centuries AD. The smaller of two silver coin types, initially struck at about 3.1g. is commonly known as a siliqua. This is a modern numismatic term that relates to the ancient unit of weight in gold of the carat – c.0.19g. The name is adopted from the seed of the carob tree (Siliqua Graeca) to relate to the smallest weight in the Roman system. In reality, the original name for this denomination is unclear and siliqua is used as convention rather than based on any historical truth.

As we have already seen with the coinage of Julian, the weight of the siliqua was reduced in c.AD 357 to a coin of about 2g. In RIC the lighter coins from after this reform are termed reduced siliquae, although this is again a modern numismatic
convention. Throughout this piece I will use the term siliqua in reference to these small silver coins – the majority are later 4th century in date and the few recorded pre-AD 357 coins on the PAS are in any case hugely rare in Britain! A second reform to the siliqua occurred during the Valentinian period, c.AD 366, that refined the purity of the silver content, after which the letters PS (pusulatum) appear in mintmarks to indicate the reformed silver

There are 2,311 siliqua recorded to date on the PAS, covering the period from the c.AD 330s until the early-5th century AD. A study of these coins up until 2010 by R. Bland, S. Moorhead, and P. Walton is a key contribution to understanding siliquae recorded as single finds in Britain. The current piece covers the coins currently on the PAS from Reece Periods 17-22, c.AD 330-445, with an additional decade of recorded material. This is by no means a
comprehensive re-working of Bland, Moorhead, and Walton – there are many database records that require further work and refinement – but I have attempted to provide an overview of the volume of material for each period by emperor, mint, and distribution, as well as some of the key reverse types that might appear during recording.

Siliquae are not uncommon finds, appearing notably in the rural British landscape in the late 4th century. They experience increased copying (both plated and of good quality silver) in the
last few decades of the century and by the 5th century experience extensive clipping of the flan (see below). They are also hoarded, sometimes in large number, perhaps most notably in the Hoxne hoard – discovered in a Suffolk field in 1992 and containing 14,565 siliquae, both regular and irregular.

Reece Period 17: AD 330-348

Siliqua of Constantine II, c. AD337-340. Record ID: FASAM-B403E1 (Copyright: Portable Antiquities Scheme, License: CC-BY).

Siliquae from prior to the weight reduction of c.AD 357 are rare as single finds in Britain and indeed there was only a single example of Constantius II within the Hoxne hoard (Hoxne no.
81). A total of 13 coins have so far been identified within the PAS material that belong in Reece Period 17 running up to AD 348. All are of the sons of Constantine, with Constantius II (AD 323-361) the most prolific (seven coins) amongst a very small total. These early fullweight coins appear to have been removed from circulation relatively quickly and they only appear in very small quantity in hoarded assemblages. As might be expected, the Gallic mints are best represented with seven coins in total (5 from the mint of Trier and 2 from Arles), with just single examples from Rome, Siscia, and Constantinople. None of the coins from this period on the PAS appear clipped and all that have been imaged appear to be regular issues of the official mints. This is currently the earliest siliqua on the PAS, struck not long after the introduction of the denomination in the AD 320s. 

This is currently the earliest siliqua on the PAS, struck not long after the introduction of the denomination in the AD 320s. Odd single examples of types from the AD 340s are recorded for Constantine II and Constantius II, however the most frequently seen reverse type for this period is VICTORIA DD NN AVGG depicting Victory advancing left holding wreath and palm – there are 9 examples currently identified on the PAS, such as CAM-4FAB91 and BERK-A6C946.

Reece Period 18: AD 348-364

Siliqua of Constantius II dating to c.AD 353-355. Record ID is SUR-8F6F7A (Copyright: Surrey County Council, License: CC-BY).

In contrast to the preceding period, Reece Period 18 sees a sudden increase in the volume of siliquae seen and recorded through the PAS. Almost without exception these post-date the reduction in weight of the siliqua between c.AD 355-357, the majority of coins issued by Constantius II (212 coins) and Julian (as both caesar and augustus – 550 coins), with smaller totals for Jovian (28 coins). A single siliqua is so far known for Magnentius, which pre-dates the weight reduction (BERK-3722F9). This is perhaps not unexpected, since the siliqua was produced in far greater quantity after c.AD 355 and in fact it is in Reece Period 18 that we see the largest totals of any period in Britain. The Gallic mints of Trier, Lyon, and Arles make up all but 12 of the so-far identified examples on the PAS, Arles alone comprising 43% of the total. Of this number, at least 90 coins are probably contemporary copies (the majority plated) and of those records with images (575 coins) at least 130 (c.22%) show some evidence of clipping.

There are only a handful of Reece Period 18 siliquae that are of the heavier pre-AD 357 weight standard, including the sole example of Magnentius on the PAS. At Lyon the Victory type of Reece Period 17 continues on the reduced weight standard, with almost 50 PAS examples (IOW-B45BF0), but the majority of siliquae from this period have reverses with vota legends within wreaths celebrating the anniversaries of Constantius, Julian, and Jovian (BERK-DDABD3 and GLO-9E8F6A).

Reece Period 19 – AD 364-378

Siliqua of Valentinian I dating to AD 364-375. Record ID is SUR-1025E2 (Copyright: Surrey County Council, License: CC-BY).

The Valentinian period (Reece Period 19) sees a continuation of quite large numbers of siliquae in use, albeit reduced from the initial burst of activity at the end of the Constantinian period. Valens followed by Valentinian I appear most frequently and it is the two VRBS ROMA issues with reverse depicting Roma seated left on a throne or cuirass from the mint of Trier that is by far the most common type, comprising more than 200 examples (see below). Trier is the dominant mint in this period – a feature also noted in the Hoxne coins and after c.AD 366 we see the addition of the letters PS (pusulatum) on mintmarks to indicate the
official improvement of the silver content (e.g. TRPS at Trier or MDPS at Milan). Within the PAS data the western mints are again prolific, although it is worth noting that eastern mint coins do still appear, notably for Valentinian I, albeit in smaller quantity. Copies are more limited in number (c.40 coins) but now approximately 40% of the regular coins demonstrate some evidence for clipping.

Lyon and Arles struck short issues with the RESTITVTOR REIP (‘Restorer of the State’) reverse type for Valentinian and Valens between AD 364-367 (at least 110 PAS examples). There are also small numbers of coins with vota legends, notably from Rome (WILT-7B8A43) as well as a Victory type for Valentinian II following his father’s death in AD 375. A large proportion of the coins from this period relate to the two VRBS ROMA issues from Trier. Trier was by this time the principal mint in Gaul striking silver, exclusively so by the end of the period (silver disappears at Arles and Lyon between AD 375-378). The first VRBS ROMA issue, struck between AD 367-375, depicts Roma seated left on a throne. A second VRBS ROMA issue was struck following Valentinian’s death in AD 375 but this time Roma is seated on a cuirass. The diagnostic details are explored in RIC and Hoxne and these should be your reference when recording coins of this period.

Reece Period 20: AD 378-388

Siliqua of Theodosius I dating to AD 379-83. Record ID is HAMP-8F4137 (Copyright: Winchester Museums Service, License: CC-BY).

Following Valens’ death in AD 378, Theodosius I, Gratian, and Valentinian II ruled as augusti. Magnus Maximus’ usurpation against the augustus in the west, Gratian, in AD 383 led to the former assuming power with his son Flavius Victor and issuing siliquae from Trier, Aquileia, and (after AD 387) Milan in his and the names of the other two augusti between AD 383-388. Gratian was killed during Maximus’ rise to power in AD 383 and so his
coinages disappear at this time; a 6-year-old Arcadius had been elevated to augustus by his father, Theodosius I, at the start of that year. 

Trier is the dominant mint again, particularly during the period of Maximus’ usurpation, followed by the Italian mints of Milan and Aquileia. The output from the mints of
Lyon and Rome was smaller at this time and this is reflected in the very few PAS examples from each. Although there are even fewer copies during this period, clipping increases again
to almost 50% of the total.

Until Maximus’ usurpation, a CONCORDIA AVGGG reverse type was struck for Theodosius I (HAMP-8F4137), a VICTORIA AVGGG type for Valentinian II (YORYM-754EAF), and a VIRTVS ROMANORVM type for Gratian (SUSS-D0CCA4) as specific reverses for each emperor. At Lyon and Rome the VRBS ROMA types seen in Reece Period 19 continue – with cuirass at Lyon and with throne at Rome, the former only running until AD 383, not striking silver under Maximus.  The VIRTVS ROMANORVM type, specific to Gratian to begin with, extends to all of the emperors and the mints of Trier, Lyon, Aquileia, and Milan from the period of usurpation onward (DEV-A02090). This type accounts for over 170 of the PAS examples from this period (c.65%). There are many minor variants within and between the mints – the Hoxne catalogue is by far the best source for this issue.

Reece Period 21: AD 388-402

Siliqua of Arcadius dating to AD 388-402. Record ID is WILT-7B0682 (Copyright: WILT-7B0682, License: CC-BY).

After Maximus’ usurpation was ended, Valentinian II was restored as ruler in the west with Thoeodius and Arcadius in the east. Valentinian’s suicide in AD 392 resulted in a second period of usurpation, by Eugenius (between AD 392-394) and Theodosius’ elevation of his second son, Honorius, to augustus in AD 393. Theodosius’ death in AD 395 ultimately left the empire ruled by Arcadius in the east and Honorius in the west.

By AD 388 the mint at Aquileia had disappeared and although Trier and Lyon struck silver in some quantity – the latter particularly during Eugenius’ usurpation – both ceased operation
by AD 395. Milan became the main source for siliquae after this period until it too closed in AD 402. The majority of siliquae recorded on the PAS from this period are from Milan (c.62%) and many demonstrate extensive clipping – at least 70% of examples have some evidence of clipping (see below). Copies are again prevalent (c.50 coins) and many of these are also clipped.

Trier and Lyon strike VRBS ROMA issues similar to Reece Period 20 with Roma seated on a cuirass (WILT-7B0682), at Lyon this is also struck for Eugenius, while at Milan there are vota issues for the augusti (GLO-1E37D9). The most prevalent reverse type in this period, however, is VIRTVS ROMANORVM (PUBLIC-EC8194 and WILT-10C298) with a similar type to the VRBS ROMA issue, depicting Roma seated left on a cuirass, struck at Trier and then (after c.AD 397) Milan. This accounts for well over 80% of the recorded siliquae on the PAS from Reece Period 21 (in Hoxne, Guest (2005, p. 74) notes that the second Milan VIRTVS ROMANORVM issue makes up just under a third of the entire hoard, more than 4,600 coins). Coins from both mints are very similar, but there are stylistic differences to both obverse and reverse type that allow for identification even on very clipped coins – Hoxne is again the best source for this.

Reece Period 22: AD 402-445

Siliqua of Constantine III dating to c.AD 407-408. Record ID is SF-DAC220 (Copyright: Suffolk County Council, License: CC-BY).

The closing of the mint at Milan in AD 402 effectively stopped the supply of siliquae to the western provinces and particularly Britannia. Silver was now issued in small quantity by the
imperial court, but it did not extend far – there are only 8 coins of this period in the Hoxne hoard (whose terminal coins date to c. AD 407/408).

By AD 402 the British garrisons had been stripped and withdrawal of Roman interest in the province was in full swing. With renewed threat from Gaul, a new usurper was elected in
Britain, Constantine III (AD 407-411), who proceeded to face the challenge head on and took what remained of the British armies across the channel. In Rome, the Visigothic invasion had pushed Honorius to Ravenna and in AD 410 Rome was sacked by Alaric. If we are to believe Zosimus, the Roman administration in Britain had already been expelled by this time, perhaps in AD 409. Although Constantine was tolerated for a time by Honorius (who had his own problems to deal with!), this didn’t last long and he was executed in AD 411 after defeat at Arles.

For a brief period of time Constantine struck siliquae at Lyon but in relatively small quantity. Only two examples are recorded in Hoxne and there is just one, incomplete, coin on the PAS
(SF-DAC220). These very rare siliquae have a reverse type reading VICTORIA AAAVGGGG, references four augusti (Honorius, Arcadius, Theodosius II, and Constantine III) and date the issue to before Arcadius’ death in AD 408 (se Guest, 2005: p. 76).


The phenomenon of clipping silver siliquae is a characteristic, and specifically British, phenomenon at the end of the 4th century and into the 5th century AD. Small quantities of the
edge of the coin flan are removed while respecting the imperial portrait, thereby seemingly enabling the original coin to remain in circulation. In his study of the Hoxne hoard, P. Guest (2005: chapter 7) explored the phenomenon at length and highlighted the various ‘clipping factors’ evident on the coins within the hoard in order to analyse the development of the phenomenon through time. In the image below examples of several PAS coins (regular and irregular!) demonstrate these various levels of clipping.

“Clipping factor” of Roman siliquae, after Guest, 2005: p.111, fig. 7.

When clipping occurred has been a subject of discussion8
. It appears to have been a 5th century phenomenon related to the cessation of supply to Britain after AD 402 and many hoards of this and slightly later date, like Hoxne, have extensive quantities of clipped siliquae. Siliquae hoards from Terling (c.AD 404) and Stanchester (c.AD 406) are unclipped and suggest that clipping began after this date and plausibly after Constantine III’s rise to power. Interestingly, a hoard of clipped siliquae found in the Pyrenees is perhaps evidence of Constantine’s army in Gaul after AD 407. The silver from clipping may well have been used
either as bullion or to top up the currency in circulation after the regular supply ceases in AD 402 (see Abdy, 2013; Guest, 2005). This may have continued for some time after AD 402 with clipped regular coins and copies circulating together, some copies even subject to clipping themselves (IOW-E24202).

Copies of siliquae appear as early as Reece Period 18 when the majority are plated. After the Valentinian reform to the silver, copies tend to be good quality silver and later also the subject of clipping. By the 5th century it may be that clipping was semi- if not an official process in Britain due to the lack of coin supply.10 Whichever may have been the case, it is apparent that towards the end of the 4th century and into the 5th clipping increases. Analysis of the PAS data by R. Bland, S. Moorhead, and P. Walton in 2013 demonstrated that the quantity of clipping increased from c.25% in Reece Period 19 to 40% (Reece Period 19), 55% (Reece Period 20), and finally 77% (Reece Period 21). A brief analysis of current PAS records in the figure below shows that this general trend has been maintained, with clipping becoming increasingly common on coins produced later in the 4th century.

Overview of clipping on coins recorded through the PAS.

This, I hope, provides a brief introduction to this commonest of 4
th century silver types. There is much detail for the wide variety of individual types produced during the 4th century that cannot be looked at in detail here. The Hoxne volume is vital in this regard, although RIC remains important too. When recording these coins through the PAS it is important to note whether the coin is clipped or not, the more this data is recorded the more we can add to the hoard evidence and understand the use and circulation of these coins in the 4th and 5th centuries AD.