I really should know the answer to this question, but I confess I do not. Pictured are two coins, both of Constantine with the Sol reverse, and both from the first officina of the Lugdunum mint. But they are obviously two different sizes. The larger one (22 mm; 5.18 g) was struck 313-314 AD; the smaller one (19 mm: 3.27 g) was struck in 316 AD. Can somebody offer an explanation for the two different sizes? What’s the historical or economic context for the change? Of course, pile on here with anything you want. But here’s a challenge, should you choose to accept it: post two coins of the same type, but of different denominational sizes.
Beautiful coins! Proud owner of an ex C_A coin, too! Congratulations. This one is minted 309 or 310 A.D., and, although I don't know the actual sizes yet, I'm assuming it's also around 5g, being the larger module. Pretty sure the size of the follis was reduced over the years. Here's my Lyons mint Sol:
My completely amateur-ish guess is that they were both minted right around the time that it was decided to reduce the size/weight of the follis due to the economic issues of the time.
Here are three. Two from the London mint and one from Trier. All have different weights and sizes ranging from 18mm, 20mm and 24mm. The largest at 24mm was also the earliest minted. CONSTANTINE I AE2 Follis OBVERSE: Constantine I AE3. 315-316 AD. IMP CONSTANTINVS AVG, laureate, cuirassed bust right REVERSE: SOLI INVICTO COMITI, Sol, radiate, standing left, chlamys across left shoulder, holding globe, right hand raised, S-F across fields, MLN in ex. Struck at London 315-16 AD 3.1g, 20mm RIC VII 43 CONSTANTINE I AE2 OBVERSE: IMP CONSTANTINVS PF AVG- Laureate, draped and cuirassed bust right REVERSE: SOLI INVIC-TO COMITI T-F across fileds, PLN in ex.- Sol standing left, raising hand and holding globe Struck at London 310 AD 4.0g, 24mm RIC VI Londinium 121a/122 CONSTANTINE I AE3 OBVERSE: CONSTANTINVS P F AVG, laureate and cuirassed bust right REVERSE: SOL INVICTO COMITI, Sol, radiate, standing left, raising right hand, globe in left, chlamys across shoulder Struck at Trier 313-15 AD 3.78 g, 18-19 mm RIC VII Trier 42
I got the small coin via AMCC 1. Was that one of yours? I am happy to have it. Initially I thought, “I didn’t need to get that one. I already have that type from Lyon,“ but when it arrived, I could see the size differential, which prompted this query. I guess you can learn something from any coin.
The plummeting size/value of the Roman coinage is a major topic we colectors study. Perhaps the finest example is what happened to the Falling Horseman coin between 350 and 360 AD. The first were well made had silver and were over 22mm. The last were scrappy and tiny. Between the extremes were several gradual steps. (date error corrected - Thanks GS!)
I have not had the coin out for some time, so I measured it again to make sure it was not a typo. It is most definitely 24mm
Very cool coins @Gavin Richardson I can offer a medieval example of two coins minted in the name of Edward III. While generally considered Anglo-Gallic coins, evidence points to them being coined in England or the Low Countries for Edward's military campaigns there. The first coin it's an Esterlin and the second coin is.a Demi-Esterlin. Edward III AR Esterlin 1335-1337 A.D. Bordeaux mint? (18mm 1.32g) Obv: EDWARD' REX AnGL' Crowned bust facing slightly left, leopard below Rev: DVX AQV ITA nIE long cross pattee terminated in trefoils, crowns in quarters Elias 56 Edward III AR Demi-Esterlin 1335-1337 A.D. Bordeaux mint? (14mm 0.57g) Obv: EDWARD' REX AnGL' ;Crowned bust facing slightly left, leopard below. Rev: DVX AQV ITA nIE; long cross pattee terminated in trefoils, crowns in quarters. Elias 57
Just so as not to confuse anyone, I think Doug meant "350 and 360 AD." There are two things going on with coins of Constantine. One is the general reduction in size of the coins that occurred several times over the span of his reign. Sometimes they was denoted by a modification of the reverse desing, as in the two coins below, one with two standards on the reverse and one at the new, reduced size with just one: Antioch mint, A.D. 330-335 RIC 86 Obv: CONSTANTI-NVS MAX AVG Rev: GLOR-IA EXERC-ITVS - Two soldiers with spears and shields; two standards between them SMANA in exergue 17 mm, 3.1 g. Heraclea mint, A.D. 335-337 RIC 150 Obv: CONSTANTI-NVS MAX AVG Rev: GLOR-IA EXERC-ITVS - Two soldiers with spears and shields; one standard between them SMHA in exergue 16 mm, 1.4 g. Sometimes there was no indication, they were just gradually reduced in size over time. This is the case with the SOLI INVICTO type and its variants. In these two above cases the smaller coins traded at the same value as the larger. Often, this resulted in larger coins getting pulled out of circulation and hoarded, which explains why it is often easier to find examples of the larger coins in nice condition than the smaller. But you asked for examples of the same reverse type appearing on different denominations. That is less common, but it did happen. Jupiter reverse: Bronze Nummus Cyzikus mint, A.D. 317-320 RIC 8 Obv: IMP CONSTA-NTINVS AVG Rev: IOVI CONS-ERVATORI AVGG - Jupiter leaning on scepter, holding Victory on globe SMK in exergue; wreath in left field, [gamma] in right 18 mm, 3.4 g. Bronze Half Nummus Nicomedia mint, A.D. 321-324 RIC 43 Obv: IMP C FL VAL CONSTANTINVS P F AVG Rev: IOVI CONS-ERVATORI - Jupiter, leaning on eagle-tipped scepter, holding Victory on globe; eagle with wreath at feet to right, captive to left SMNB in exergue; X over IIM (truncated) in right field 19 mm, 2.7 g. Sol reverse: Nummus Ticinum mint, A.D. 312-313 RIC 131a Obv: CONSTANTINVS P F AVG Rev: SOLI INVI-C-TO COMITI - Sol standing right, looking left, holding globe in left hand, raising right TT in exergue 23 mm, 5.0 g. Half Nummus Treveri (Trier) mint, A.D. 310-311 RIC 899 Obv: CONSTANTINVS AVG Rev: SOLI IN-VICTO - Sol holding globe; right hand raised PTR in exergue 18 mm, 1.4 g.
Yep, that small one was mine! It was time to see that cute face of Sol go. I'm glad it found a great home! Here's a large module one from Trier:
from RIC VII, the mean weights in grams A.D. 310 5.2g A.D. 312 4.5g A.D. 314 3.75g A.D. 318 3.35g A.D. 322 3.0g A.D. 330 2.25g A.D. 335 1.50
Perhaps you intended for us to post Roman only, but here are various denominations of Klazomenai "Pigasus" coins from c. 500-400 BCE : The denomination nomenclature seems to be unsettled. The largest coin is 6.77 gm. I've seen it called a drachm, didrachm, and stater. The next largest coin is 3.33 gm and I've seen it called a drachm and a hemidrachm. The next two are the most common and are usually listed as diobols but I've also seen them called tetrobols (?!, "tetrobol" must be a mistake); the weights of the coins shown are 1.0 gm and 1.2 gm, respectively. Lastly is a 0.27 flake of a coin, usually called a hemiobol which makes sense given the weights of the diobols.
The problem continued for some time , my collection is 800 years later and the smallest denomination always lacks written conformation on how they were used. A few years back a catalog dealing with 12th century Eastern Roman coinage tried confirm denominations with die sizes, it does work but with issues. One of the Authors Val rushed his work and did not seem to have enough examples to check. He passed away from Cancer shortly after publishing. I pursued the die size theory and found he missed some of the sizes. The coins of Alexius Comnenus and his son John II were spot on but the weights varied greatly, in some cases the same denomination went from 1gm to 6gm. Rulers after that, Manuel, Andronicus and Isaac II had three die sizes for the same type of coin, 18mm, 15mm and 12mm. Most of the catalogs have the denomination broken into two sizes , the reason was the author of work that wrote the basis of the Alexius reform suspected their was multiple denominations but was unable to prove it, so the coins were broken into two average weights. Not to overcomplicate the issue but after I found the three sizes I was curious if they co circulated or were just debased coins. Since tetartera hoards are extremely rare we are really just left with the coins themselves to answer the problem. This coin Manuel SBCV-1980 adds to my argument they were cocirculating and were different denominations. This coin has two different die sizes be used. 15mm and 12mm and I have seen other mismatched dies. Not many only one or two others.
That’s a really attractive denominational set, @TIF. When pigs fly, indeed. Interesting stuff, @BenSi. Looks like you have something important to contribute to understanding those Byzantine issues.