Using coin
rarity info from dirtyoldcoins.com/Roman-Coins-Blog/1267 and after spending a few hours hunting down the number of
search results on CoinsArchive.com for the
denarii of the emperors up to
Gordian I and II (designing the searches as much as possible so that only the relevant coins would be counted), I came up with this graph (attached). It depicts on the y
axis how
rare the
denarius of emperors are relative to those of
Augustus (whose
denarii are the most common), and on the x
axis how the coins of all
denominations are relative to those of
Augustus. So the coins of
Nero, whose point is at (2.1, 6.0), are 2.1 times rarer as those of
Augustus, while
his denarii appear 6 times rarer than those of
Augustus. Both axes are on a log
scale.
The numbers alongside the names of the emperors is the market availability of that emperor's
denarius relative to the availability of
his all
his coins. It is the number of
denarii of that emperor recently available on the market divided by the number of coins in all
denominations that were recently available for that emperor. So for each
Caligula denarius on the market, there are 15.5 available
Caligula coins of all
denominations.
This graph is shocking. Of the 27 emperors here, there are only three emperors for which this ratio is above 6:
Nero,
Caligula, and
Claudius. For each
denarius of
Claudius on the market, there are a massive 274 available
Claudius coins of all
denominations.
Why are most coins of the Emperor Caligula rare?
Answer: They were recalled by the Senate and melted down. After his death, the Senate decreed (among other things) that all of Caligula's coins be recalled from circulation and melted down. Although his reign lasted only about four years, his coins are much scarcer than those of Titus, who reigned for only two years.
This does not explain why Caligula's silver coins are 15.5 times rarer on the market than all of
his coinage taken together. Presumably the Senate would have destroyed base metal and
gold coins too.
This is a very subjective issue, ie; what types of searches are you doing to check for dealers;ie, ebay, craigslist, local coin club or the more exclusive dealers...
With respect, the
rarity of
Claudius denarii is more than just an impression, it is quantifiable.
His denarii are
rare both with respect to those of
Augustus (246 times rarer) and with respect to
his own coinage (273 times rarer than all
his other coins combined).
Gordian II ruled for 21 days in AD 238 and
his denarii seem to appear almost four times more often on the market than those of
Claudius, who ruled 14 years.
One of the explanations given above is that
Nero recalled the silver coins in circulation and re-minted them with debased silver. This would explain both the
rarity of Claudius's and Caligula's silver coinage. The problem with this explanation is that one would have expected Tiberius's silver coins to have been partially melted too, but this is not evidenced in the graph.
The number of Claudius's
denarii on the market relative to those of
Caligula is also intriguing and I believe important to answer the question of Claudius's "missing
denarii". Suppose
Claudius had continued to
mint denarii at the same frequency as
Caligula for the first four years of
his reign and then stopped producing them completely. In this scenario, because
Caligula reigned four years, there would have been at the start of Nero's reign a comparable number of
Caligula and
Claudius denarii in circulation. (The extra 1-4 years that Caligula's
denarii would have
had to be lost in the ground and preserved for numismatists compared to those of Claudius's
denarii can be neglected). Yet there are 6 times more
Caligula denarii on the market than
denarii of
Claudius. In my opinion, this strongly argues against the
Nero reminting hypothesis, for this would have required selectively reminting the
denarii of
Claudius over those of
Caligula.
There seems to be far too few
Claudius denarii on the market to argue that they were actually minted but by some process destroyed before they reached us. I believe
Claudius simply produced fewer
denarii. Why? I'm as baffled as you are.
