Diocletian IOVI CONSERVAT AVGG reduced sestertius from Rome

[Victor]

Here's a neat coin that just sold--

Diocletian (AD 284-305). AE reduced sestertius (23mm, 5.54 gm, 1h). NGC Choice XF★ 5/5 - 3/5. Rome, ca. AD 285. IMP DIOCLETIANVS AVG, laureate, draped bust of Diocletian right, seen from behind / IOVI CO-NS-E-RVAT AVGG, Jupiter standing facing, head left, thunderbolt in outstretched right hand, grounded scepter in left. Cf. RIC V.II 202 (semis) var. (rev. legend).

[Heliodromus]

Yes, interesting coin, and RIC totally botches the cataloging of these.

I'm pretty sure this one is more than just a RIC 202 variant (and not just because of the misreported legend), and actually a separate issue - the final sestertius issue.

As far as the legend goes, I've yet to see anything corresponding to RIC 199 or 200 (Diocletian) with RIC's "CONSEVATORI" legend - they all seem to be "CONSERVAT", so this is minimally the more common legend, and seems likely just an error in RIC. For the same type with reverse of Maximianus (RIC 535), RIC reports the legend correctly.

As far as issues, Diocletian's first sestertius has to be RIC 200 with it's singular PAX AVG legend, which must date to his sole rule of 284-285 AD, and then following that, presumably c.286 AD we have IOVI CONSERVAT AVGG - with spread chlamys - RIC 199/202 for Diocletian and RIC 535 for Maximianus. The bust style for Diocletian follows that of RIC 200 (PAX). Likely at the same time, but with different cuirassed bust types, we have VIRTVS AVGG (Hercules with trophy) - RIC 201 for Diocletian and RIC 536 for Maximianus.

Now the more interesting bit ... the coin you show that Heritage just sold (and another similar one in the BM) is different from the IOVI of this first group in two ways - the reverse has jupiter without spread chlamys (which RIC omits to mention for 199/202 & 535), standing a little taller with his head breaking the legend, and a completely different bust style for Diocletian strongly suggesting a different date. RIC dates RIC 199+535 to beginning of their joint rule c.285 (286?) AD, but Diocletian's RIC 202 to 291 AD, so it's possible RIC 202 is referring to this later jupiter without spread chlamys type despite RIC 199 & 202 both being described the same.

What seems to nail the date for this Heritage/BM type is an unlisted PRINCIPI IVVENTVTI sestertius of Galerius as caesar that I discovered when trying to find a match for this distinctive Diocletian bust style. This Galerius coin is in the U.Albert-Ludwigs collection, and measures 23mm 5.37g - too large/heavy for an AE denarius or post-reform laureate, so must be a sestertius, and obviously has to date to the beginning of the tetrarchy in 293 AD. The bust style for Galerius is an extremely close match to that for Diocletian on this later IOVI type, so it seems that must also belong to this unlisted 293 AD sestertius issue (final one before coinage reform in following year).

During the tetrarchy we expect to see some symmetry in the coinage for Dioclatian and Maximianus, so it seems that this late IOVI type for Diocletian should be paired with a late VIRTVS (Hercules) one for Maximianus, and RIC 535 seems to fit the bill with a different bust type for Maximianus and a different depiction of Hercules with bow. I'd provisionally assign this RIC 535 type to the same 293 AD final sestertius issue.

Finally a note on the sestertius denomination for these types, as typically cataloged, which I assume is correct despite RIC's description of them as variously asses and semisses. I assume this is described somewhere, but not in anythng I have access to. For Diocletian's pre-reform "AE" types we have "AE denarii" of ~3g, "AE quinarii" of ~1.5g and these "AE sestertii" of ~5g. Clearly these weights make no sense if all are in fact "AE" since a sestertius is 1/4 denarius! I suspect that in reality the "AE" denarii and quinarii are 5% silver billion, and the sestertius pure bronze, which would then make the bullion values align per silver and bronze prices reported in Diocletian's edict on maximum prices. One counter-intuitive aspect of the 5% billion denominations is that almost 85% of their value derives from the 5% silver content, with bronze valued at 0.18 DC/g and silver at 18.24 DC/g.

For these denarii/quinarii/sestertii we'd therefore have:

~3g 5% billion denarius = 3.24 DC (1 den)
~1.5g 5% billion quinarius = 1.62 DC (1/2 den)
~5g AE sestertius = 0.90 DC (1/4 den)

I've not seen any confirmation that the "AE" denarii and quinarii are in fact 5% billion vs pure bronze, but this seems to be the only way to make the values align per the weights.

RIC groups these sestertii into two weights which it refers to as assess and semisses, but I believe they are all the same nominal weight standard of ~5g with the variation being due to the normal lax bronze weight control.

So, in summary:
- Not in RIC sestertius issue of 293 AD including Galerius CAES PRINCIPI IVVENTVTI
- Diocletian IOVI without spread chlamys assigned to this 293 AD issue based on bust style

[ultimateprice]

I haven't been active here in a long time, but talk of tetrarchic sestertii has enticed me! Excellent work, Heliodramus. I wholeheartedly agree that all these late bronze issues are sestertii and not semisses and asses as RIC and others suggest. Bit of an aside, but I've found a die match between a so-called Probus as and a so-called semis. Weight really never mattered for Roman imperial bronzes, it just doesn't make sense to get finicky about it for this period. It's been suggested to me by some experts that perhaps we're looking at one denomination here that's undergone weight reductions, but I just don't buy it. I'll share photos of my Diocletian and Maximian sestertii below.

That Galerius is really incredible. It seemed odd that they'd stop minting these larger bronzes before the coinage reform, but I had never seen one of a Caesar before. Now we need to find one of Constantius!

[ultimateprice]

My Diocletian is in the same style as the Heritage example. My Maximian has been smoothed and tooled a bit, but it shares a reverse die with 202, the Diocletian sestertius from Triton years past.

 

[Heliodromus]

Thanks for posting those pictures. Interesting to see that Diocletian obv/rev combination - presumably transitional, assuming both IOVI reverse types weren't used in parallel.

Another type not mentioned yet is Hercli Pacifero (RIC 532 - Roma XX.676 specimen below) for Maximianus, which may also have a yet-to-be discovered counterpart for Diocletian (a non-AVGG IOVI type such as IOVI FVGERATORI perhaps?). The bust style isn't a slam-dunk match for the other issues, so another potential occasion fore issue would have been their quinquennalia of 290-291 AD.

[ultimateprice]

You're welcome! Yes, I agree with you on both counts. I actually have the IOVI FVLGERATORI Quinarius for Maximian.

Maximian. First reign, AD 286-305. Æ Quinarius (14mm, 1.40 g, 11h). Rome mint. Struck AD 290. Laureate, draped, and cuirassed bust right / Jupiter advancing left, head right, hurling thunderbolt with his right hand; to left, eagle standing left, head right. RIC V 522 corr. (bust type); King 36 corr. (no scepter). Extremely rare, only 3 known to King, none in CoinArchives.

[Heliodromus]

Great coin!